Faculty Profiles - SUZUKI Atsushi

Papers - SUZUKI Atsushi

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Effects of light irradiation on the photovoltaic performance and crystal lattices of organic–inorganic perovskites in solar cells International journal

Haruto Shimada , Takeo Oku Tomoki Yamamoto, Iori Ono, Atsushi Suzuki, Kouichirou Harada,

Next Energy 8 100263 2025.3

Fabrication and Characterization of CH3NH3PbI3 Perovskite Photovoltaic Devices with Decaphenylcyclopentasilane Hole Transport Layers Reviewed

Keisuke Kuroyanagi, Takeo Oku, Iori Ono, Haruto Shimada, Atsushi Suzuki, Tomoharu Tachikawa and Sakiko Fukunishi,

Coatings 15 253 2025.2

Fabrication and Characterization of Perovskite Solar Cells Using Metal Phthalocyanines and Naphthalocyanines

87 ( 1 ) 6 2025.2

Effects of K- or Ge-additions to formamidinium-based perovskite crystals on electronic structures and photovoltaic properties

Ryo Sobajima, Takeo Oku, Riku Okumura, Iori Ono, Atsushi Suzuki, Tomoharu Tachikawa, Tomoya Hasegawa, Sakiko Fukunishi

Chemical Physics Letters 865 141937 2025.2

First-principles calculation on electronic structures, phonon dispersions, electronic and thermal conductivity and molecular dynamics of CsYbCl3 perovskite crystal

Atsushi Suzuki, Takeo Oku

Computational Condensed Matter 42 e01008 2025.1

Promoted formation of photoactive α-formamidinium cesium lead triiodide perovskite crystals by germanium addition Reviewed

Ayu Enomoto, Atsushi Suzuki, Takeo Oku and Haruto Shimada

Inorganics 13 15 2025.1

Electronic structures, thermal properties and molecular dynamics of CsGdCl3 and CsNdCl3 perovskite crystals by first-principles calculations

Atsushi Suzuki, Takeo Oku

Journal of Physics and Chemistry of Solids 194 112243 2024.8

Efects of metal phthalocyanine and naphthalocyanine on perovskite solar cells Reviewed

Atsushi Suzuki, Naoki Ohashi, Takeo Oku, Tomoharu Tachikawa, Tomoya Hasegawa, Sakiko Fukunishi

Journal of Electronic Materials 53 6049 - 6063 2024.7

Effects of neodymium or ytterbium addition to CH3NH3PbI3 perovskite solar cells inserted with decaphenylcyclopentasilane Reviewed

Kotaro Yamamoto, Atsushi Suzuki, Riku Okumura, Ayu Enomoto, Iori Ono, Takeo Oku, Sakiko Fukunishi, Tomoharu Tachikawa, Tomoya Hasegawa

Results in Surfaces and Interfaces 15 100224 2024.5

Accelerated formation of photoactive formamidinium-based lead triiodide perovskite crystals by the addition of copper iodide Reviewed

Riku Okumura, Takeo Oku, Atsushi Suzuki

Chemistry of Inorganic Materials 3 100052 2024.4

Electronic structures of lead-free Sn- or Ge-hybrid perovskite halides studied by first-principles calculation Reviewed

5 100174 2024.3

Effects of guanidinium iodide surface treatment on CH3NH3PbI3 perovskite solar cells with added decaphenylcyclopentasilane Reviewed

Keisuke Kuroyanagi, Takeo Oku, Iori Ono, Riku Okumura, Ayu Enomoto, Atsushi Suzuki, Sakiko Fukunishi, Tomoharu Tachikawa, Tomoya Hasegawa

Nano Trends 5 100030 2024.2

Effects of alkali metals or Cu+ addition to α-FAPbI3 perovskite crystals on electronic structures and photovoltaic properties Reviewed

Riku Okumura, Takeo Oku, and Atsushi Suzuki

Japanese Journal of Applied Physics 63 02SP21 2024.1

Effects of ethylammonium and rubidium addition to guanidinium-based CH3NH3PbI3 perovskite photovoltaic devices prepared at 190 ◦C in ambient air Reviewed

Iori Ono, Takeo Oku, Atsushi Suzuki, Sakiko Fukunishi, Tomoharu Tachikawa, Tomoya Hasegawa

Materials Today Communications 38 107623 2023.11

Electronic structures and photovoltaic properties of copper- or tin-doped cesium-based perovskite crystals Reviewed

Ayu Enomoto, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, Tomoharu Tachikawa, Tomoya Hasegawa

Open Ceramics 16 100476 2023.9

Electronic structures and properties of lead-free cesium- or rubidium-based perovskite halide compounds by first-principles calculations Reviewed

Riku Okumura, Takeo Oku, Atsushi Suzuki

Nano Trends 4 100020 2023.9

Electronic structures and molecular dynamics of gadolinium-doped FAPbI<inf>3</inf> perovskite crystals Reviewed

Suzuki A., Oku T.

Japanese Journal of Applied Physics 62 ( SK ) 2023.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics

The additive effect of a gadolinium ion into a formamidinium lead iodide (FAPbI3) perovskite crystal on electronic structures and molecular dynamics was investigated for improving photovoltaic performance with stability. The electronic structures, band structure, partial density of state, and molecular dynamics were determined by first-principles calculation. The band distribution and charge transfer between the 5d orbital of the gadolinium atom, the 5p orbital of the iodine atom, and the 6p orbital of the lead atom promoted the carrier generation and diffusion related to short-circuit current density. The enthalpy and kinetic energy prompted stabilization of the gadolinium-doped crystal with a slight distortion of coordination structure, as compared with the decomposition of the FAPbI3 crystal. Diffusion coefficients of iodine and lead ions in the FAPbI3 crystal with defect were increased, predicting decomposition. The gadolinium-doped FAPbI3 perovskite crystal has great potential for applications in photovoltaic devices by improving photovoltaic performance.

DOI： 10.35848/1347-4065/acbec0

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First-principles calculations and device characterizations of formamidinium-cesium lead triiodide perovskite crystals stabilized by germanium or copper Reviewed

Enomoto A., Suzuki A., Oku T., Fukunishi S., Tachikawa T., Hasegawa T.

Japanese Journal of Applied Physics 62 ( SK ) 2023.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics

To avoid formation of the photo-inactive δ-phase of formamidinium-cesium lead triiodide, copper or germanium was added to the perovskite compounds to stabilize the photoactive α-phase. It was found that the substitution of lead by germanium (Ge) or copper (Cu) provided the stabilization of the α-phase in the present work. The first-principles molecular dynamics calculations indicated that displacements of formamidinium molecules were suppressed by the Ge doping. X-ray diffraction results indicated that the Ge or Cu doping of the perovskite compounds could be effective for suppression the phase transition from α- to δ-phase.

DOI： 10.35848/1347-4065/acc6d8

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First-principles calculation analysis and photovoltaic properties of Cu compound-added perovskite solar cells Reviewed

Okumura R., Oku T., Suzuki A., Fukunishi S., Tachikawa T., Hasegawa T.

Japanese Journal of Applied Physics 62 ( SK ) 2023.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics

Experiments and first-principles calculations were performed to investigate the effects of Cu substitution in CH3NH3PbI3 perovskite crystals. The first-principles calculations indicated that the energy level of the Cu d orbital formed above the VB maximum would be an acceptor or defect level. The effect of Cu addition on device properties was investigated, and the device with added 2% Cu provided higher efficiencies than the standard device. On the other hand, the decrease in short-circuit current density with increasing Cu content would be attributed to the defect level of the Cu d orbitals. First-principles calculations and experimental results provided insight into the function of Cu in CH3NH3-based perovskite crystals.

DOI： 10.35848/1347-4065/accaef

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Metallophtalocyanine Used Interface Engineering for Improving Long-Term Stability of Methylammonium Lead Triiodide Perovskite Reviewed

Chihiro Ogawa, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, Tomoharu Tachikawa, and Tomoya Hasegawa

Phys. Status Solidi A 220 ( 12 ) 2300038 2023.6

Electronic structures and molecular dynamics of gadolinium-doped FAPbI3 perovskite crystals Reviewed

Atsushi Suzuki and Takeo Oku

Japanese Journal of Applied Physics 62 SK1006 2023.3

Additive effects of CuPcX<inf>4</inf>-TCNQ on CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> perovskite solar cells Reviewed

Suzuki A., Hasegawa R., Funayama K., Oku T., Okita M., Fukunishi S., Tachikawa T., Hasegawa T.

Journal of Materials Science: Materials in Electronics 34 ( 7 ) 2023.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Science: Materials in Electronics

Fabrication and characterization of methylammonium lead iodide CH3NH3PbI3 (MAPbI3) perovskite solar cells using decaphenylpentacyclosilane (DPPS), metal phthalocyanine complex doped with tetracyanoquinodimethane (TCNQ) as hole-transporting materials were performed. Additive effects of carboxylic acid, amino, or sulfonic acid sodium salt substituted phthalocyanine complex (MPcX4, M = Cu, Zn, Co, X = COOH, NH2 or SO3Na) doped with TCNQ on the photovoltaic properties, crystal orientation, morphologies and electronic structure were investigated. Incorporation of DPPS and CuPc(NH2)4 doped with TCNQ on the perovskite layer promoted the carrier generation and charge transfer, yielding the best performance of conversion efficiency as compared with other cases. The photovoltaic performance depended on the (100) crystal orientation in the perovskite layer. The surface modification and passivation in the perovskite layer supported the photovoltaic performance with stability under air atmosphere. The molecular interaction based on overlap of π-orbital on CuPc(NH2)4, TCNQ and the perovskite crystal promoted the charge transfer at the interface between the perovskite layer and hole-transporting layer, improving the photovoltaic performance.

DOI： 10.1007/s10854-023-10001-z

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Additive effects of CuPcX4-TCNQ on CH3NH3PbI3 perovskite solar cells Reviewed International journal

Atsushi Suzuki, Ryota Hasegawa, Kai Funayama, Takeo Oku, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa, and Tomoya Hasegawa

J Mater Sci: Mater Electron 34 588 2023.2

Fabrication and Characterization of SnCl<inf>2</inf>- and CuBr-Added Perovskite Photovoltaic Devices Reviewed

Asakawa Y., Oku T., Kido M., Suzuki A., Okumura R., Okita M., Fukunishi S., Tachikawa T., Hasegawa T.

Technologies 10 ( 6 ) 2022.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Technologies

Perovskite photovoltaic devices added with tin (Sn) dichloride and copper (Cu) bromide were fabricated and characterized. The thin film devices were prepared by an ordinary spin-coating technique using an air blowing method in ambient air. A decaphenylcyclopentasilane layer was coated at the surface of perovskite layer and annealed at a high temperature of 190 °C. Conversion efficiencies and short-circuit current densities were improved for devices added with Sn and Cu compared with the standard devices. The energy gap of the perovskite crystal decreased through the Sn addition, which was also confirmed by first-principles calculations.

DOI： 10.3390/technologies10060112

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Ethylammonium Bromide- and Potassium-Added CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> Perovskite Solar Cells Reviewed

Terada S., Oku T., Suzuki A., Okita M., Fukunishi S., Tachikawa T., Hasegawa T.

Photonics 9 ( 11 ) 2022.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Photonics

Perovskite solutions with added potassium iodide (KI) and ethylammonium bromide (EABr) were used to fabricate perovskite solar cells in ordinary air at 190 °C. The addition of EABr and KI induced (100)-oriented perovskite crystals, which resulted in the improvement in short-circuit current densities and conversion efficiencies. The short-circuit current density, open circuit voltage, and conversion efficiency of the best device were 21.0 mA cm−2, 0.942 V, and 12.88%, respectively. First-principles calculations also indicated a decrease in total energy per cell and an increase in energy gaps, which agreed with the improved results of device stabilities and photovoltaic properties.

DOI： 10.3390/photonics9110791

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Additive effect of lanthanide compounds into perovskite layer on photovoltaic properties and electronic structures Reviewed

Suzuki A., Kishimoto K., Oku T., Okita M., Fukunishi S., Tachikawa T.

Synthetic Metals 287 2022.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Synthetic Metals

Fabrication and characterization of lanthanide compound doped CH3NH3PbI3 (MAPbI3) perovskite solar cells have been performed for improving the photovoltaic properties with long-term stabilities of conversion efficiency. The purpose of this research is to investigate additive effect of formamidinium iodine (FAI) and lanthanide compound into the perovskite layer for improving carrier diffusion and mobility in the perovskite layer. Incorporation of FAI and europium chloride (EuCl2) into the perovskite crystals maintained the stability of conversion efficiency for 30 days. The photovoltaic properties were based on the crystal growth and orientation with suppression of decomposition, thermodynamic stabilities, and the narrow band dispersion with decrease of effective mass. In contrast case, addition of samarium or terbium compound reduced the stabilities, and suppressed the carrier mobility owing to the flat band dispersion of localized d orbital of samarium atom or 4 f orbital of terbium atom near valence band state. The annealing treatment improved the crystal orientation related to the carrier diffusion with inhibiting recombination, improving short circuit current density and external quantum efficiency. The perovskite crystal doped with EuCl2 and FAI have high advantage to apply for practical use of the photovoltaic devices with long-term stability.

DOI： 10.1016/j.synthmet.2022.117092

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Fabrication and Characterization of Perovskite Solar Cells Using Silicon Phthalocyanine Complex Reviewed International journal

Chihiro Ogawa, Iori Ono, Atsushi Suzuki, Takeo Oku, Masanobu Okita, Sakiko Fukunishi , Tomoharu Tachikawa and Tomoya Hasegawa

3rd International Online-Conference on Nanomaterials session Polymer Nanomaterials, Soft Nanomaterials, Nanocoatings/Thin films, and Nanostructured Surfaces 2022.4

Effects of Adding Alkali Metals and Organic Cations to Cu-Based Perovskite Solar Cells Reviewed

Okumura R., Oku T., Suzuki A., Okita M., Fukunishi S., Tachikawa T., Hasegawa T.

Applied Sciences (Switzerland) 12 ( 3 ) 2022.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Applied Sciences (Switzerland)

First-principles electronic band calculations were used to investigate the effects of alkali metals and organic cations added to Cu-based perovskite solar cells. The copper d-orbital band was slightly above the valence-band maximum and functioned as an acceptor level for carrier genera-tion. Excitation from iodine p-orbitals and copper d-orbitals to alkali metal s-orbitals could suppress carrier recombination and promote carrier transport. Experimental solar conversion efficiencies increased after adding both Cu and Na, in agreement with the calculations. Total-energy calculations indicated that the perovskite crystal stability increased with the addition of ethyl ammonium, alt-hough the total energy decreased with the addition of Cu and Na.

DOI： 10.3390/app12031710

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Fabrication and characterization of CH3NH3PbI3 solar cells with added guanidinium and inserted with decaphenylpentasilane Reviewed

Ono I., Oku T., Suzuki A., Asakawa Y., Terada S., Okita M., Fukunishi S., Tachikawa T.

Japanese Journal of Applied Physics 61 ( SB ) 2022.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics

In this work we investigated the effects of the addition of guanidinium [C(NH2)3; GA] on CH3NH3PbI3 perovskite solar cells fabricated at a high temperature of 190°C in atmospheric air. The addition of GA iodide and the insertion of decaphenylpentasilane between the perovskite and hole transport layer improved the external quantum efficiency and short-circuit current density, and the conversion efficiencies were stable after 1 month. X-ray diffraction showed that the lattice constant of the perovskite crystals was increased by the addition of GA, and addition of GA also improved the surface morphology. First-principles calculations on the density of states and band structures showed reduction of the total energy by the addition of GA and the effectiveness of the nitrogen atoms in GA.

DOI： 10.35848/1347-4065/ac2661

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Effects of copper addition to methylammonium/potassium- based perovskite solar cells Reviewed

Ayu Enomoto, Atsushi Suzuki, Takeo Oku, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 9 ( 1 ) 2022.1

Effects of Cu, K and Guanidinium Addition to CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> Perovskite Solar Cells Reviewed

Enomoto A., Suzuki A., Oku T., Okita M., Fukunishi S., Tachikawa T., Hasegawa T.

Journal of Electronic Materials 2022.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Electronic Materials

In this study, CH3NH3PbI3 perovskite solar cells with added copper (Cu) and potassium (K) or guanidinium (GA) were fabricated and characterized. The effects of the additives on the photovoltaic properties, morphology and crystalline structure were investigated, and the electronic structures and thermodynamic stabilities are discussed. The stability and conversion efficiency of the perovskite solar cell improved by incorporating Cu at the lead site and K or GA at the CH3NH3 organic cation site in the cubic crystal. Simultaneous addition of Cu and K to the perovskite crystal suppressed decomposition of the crystal by desorption of methylammonium (MA), which led to improvement of the stability of the photovoltaic device. After 28 days, the conversion efficiency of the device with co-added Cu and K was still 10.8%, whereas that of the standard device decreased to 10.1%.

DOI： 10.1007/s11664-022-09688-3

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Effects of polysilane addition to chlorobenzene and high temperature annealing on CH3NH3PBI3 perovskite photovoltaic devices Reviewed

Oku T., Taguchi M., Suzuki A., Kitagawa K., Asakawa Y., Yoshida S., Okita M., Minami S., Fukunishi S., Tachikawa T.

Coatings 11 ( 6 ) 2021.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

CH3NH3PbI3 perovskite photovoltaic devices treated with a polysilane layer were fabricated and characterized. Decaphenylcyclopentasilane (DPPS) in chlorobenzene solution was deposited at the surface of the perovskite layer, and the resulting device was annealed at 140-260 °C. The photoconversion efficiencies of the DPPS-treated device remained high even after 255 days in ambient air. Raman scattering spectroscopy and ab initio molecular orbital calculations of DPPS suggested that it increased hole transport efficiency in the treated devices, which was confirmed from the high shunt resistances of the DPPS-treated devices.

DOI： 10.3390/coatings11060665

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Effects of mixed-valence states of Eu-doped FAPbI3 perovskite crystals studied by first-principles calculation Reviewed International journal

A. Suzuki and T. Oku

Materials Advances 2 2609 - 2616 2021.3

Fabrication and Characterization of Ni-, Co-, and Rb-Incorporated CH3NH3PbI3 Perovskite Solar Cells Reviewed International journal

A. Suzuki, M. Oe and T. Oku

Journal of Electronic Materials 50 ( 4 ) 1980 - 1995 2021.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Electronic Materials Participation form：Joint(The main charge)

Ni- and Co-incorporated CH3NH3PbI3 perovskite solar cells were fabricated and characterized to optimize the photovoltaic and optical properties related to surface morphology, crystal growth and orientation, and electronic structures. Partially replacing Pb with Ni or Co in the perovskite crystals improved the photovoltaic performance and carrier mobility based on the effective mass in the band structure. In particular, the addition of both Ni and Rb compounds to perovskite improved the long-term stability of the photovoltaic cells, which depended on surface modification and coverage, crystal growth, and the high (100) orientation in the perovskite layer. The short-circuit current density of the cells was increased by promoting the generation and mobility of photoinduced carriers, which were inversely proportional to the effective mass ratio. Electron correlation was associated with the promotion of charge transfer owing to the hybridization between the 3d orbitals of Ni and the 5p orbitals of the I atoms near the valence band state.

DOI： 10.1007/s11664-021-08759-1

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Additive Effects of Guanidinium Iodide on CH3NH3PbI3 Perovskite Solar Cells Reviewed

Kishimoto T., Oku T., Suzuki A., Ueoka N.

Physica Status Solidi (A) Applications and Materials Science 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Physica Status Solidi (A) Applications and Materials Science

CH3NH3PbI3 (MAPbI3) perovskite solar cells with guanidinium (C(NH2)3+, GA+) are fabricated at 150 °C using 3CH3NH3I:PbCl2 starting composition in ambient atmosphere, and characterized. Their photoconversion efficiencies and stabilities are improved by the addition of a small amount of GA+. Lattice volumes are increased by the addition of GA+, which confirms the occurrence of GA+ substitution at the CH3NH3 site. Energy gaps are decreased by the addition of GA+, which agrees well with the results of molecular orbital calculation and band calculation. The carrier trap density is reduced by the GA+ addition, which suggests that lattice defects are suppressed by the GA+ doping. Two-year stabilities of the devices in ordinary air are also investigated, which indicate the effectiveness of GA addition.

DOI： 10.1002/pssa.202100396

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Additive Effects of Copper and Alkali Metal Halides into Methylammonium Lead Iodide Perovskite Solar Cells Reviewed

Suzuki A., Kitagawa K., Oku T., Okita M., Fukunishi S., Tachikawa T.

Electronic Materials Letters 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Electronic Materials Letters

Fabrication and characterization of methylammonium lead iodide perovskite solar cells incorporated with formamidinium iodide, copper halides, alkali metal halides and decaphenylcyclopentasilane were performed. Addition of CuCl and KI at 2% into the perovskite layer offered compact morphologies and crystal orientation in the perovskite layer, improving short circuit current densities, series resistance and open-circuit voltages related to conversion efficiencies. The stabilities of conversion efficiencies were improved for the perovskite layer incorporated with 2% CuCl and 2% NaI. The stabilities depended on the state of the surface morphologies and crystal orientation while suppressing decomposition reaction in the perovskite layer. The photovoltaic mechanisms were associated with promotion of carrier generation and diffusion in the crystalline layer. The electronic correlation was based on the charge transfer between 5p orbital of I ion and 3d orbital of Cu ion near valence band, promoting the carrier generation and diffusion related to the short circuit current densities. Graphical Abstract: [Figure not available: see fulltext.]

DOI： 10.1007/s13391-021-00325-5

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Additive effects of methyl ammonium bromide or formamidinium bromide in methylammonium lead iodide perovskite solar cells using decaphenylcyclopentasilane Reviewed

Suzuki A., Taguchi M., Oku T., Okita M., Minami S., Fukunishi S., Tachikawa T.

Journal of Materials Science: Materials in Electronics 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Science: Materials in Electronics

Fabrication and characterization of methylammonium lead iodide perovskite solar cells incorporated with methylammonium bromide (MABr), formamidinium bromide (FABr), and decaphenylcyclopentasilane (DPPS) were performed. Additive effect of MABr or FABr into the perovskite layers inserted with DPPS as hole-transporting layer was investigated. Addition of 5% MABr or FABr into the perovskite layer improved the short-circuit current density, shunt resistance, and open-circuit voltages, which depended on the uniform morphologies while suppressing defects and pinholes in the perovskite layer. The stabilities of the photovoltaic performance depended on the degree of incorporation of MABr or FABr with the DPPS layer, which suppressed decomposition in the perovskite layer.

DOI： 10.1007/s10854-021-07023-w

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Fabrication and Characterization of Ni-, Co-, and Rb-Incorporated CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> Perovskite Solar Cells Reviewed

Suzuki A, Oe M, Oku T

Journal of Electronic Materials 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Electronic Materials

© 2021, The Minerals, Metals & Materials Society. Ni- and Co-incorporated CH3NH3PbI3 perovskite solar cells were fabricated and characterized to optimize the photovoltaic and optical properties related to surface morphology, crystal growth and orientation, and electronic structures. Partially replacing Pb with Ni or Co in the perovskite crystals improved the photovoltaic performance and carrier mobility based on the effective mass in the band structure. In particular, the addition of both Ni and Rb compounds to perovskite improved the long-term stability of the photovoltaic cells, which depended on surface modification and coverage, crystal growth, and the high (100) orientation in the perovskite layer. The short-circuit current density of the cells was increased by promoting the generation and mobility of photoinduced carriers, which were inversely proportional to the effective mass ratio. Electron correlation was associated with the promotion of charge transfer owing to the hybridization between the 3d orbitals of Ni and the 5p orbitals of the I atoms near the valence band state.

DOI： 10.1007/s11664-021-08759-1

Polysilane-Inserted Methylammonium Lead Iodide Perovskite Solar Cells Doped with Formamidinium and Potassium Reviewed International journal

Takeo Oku, Satsuki Kandori, Masaya Taguchi, Atsushi Suzuki, Masanobu Okita, Satoshi Minami, Sakiko Fukunishi and Tomoharu Tachikawa

Energies 13 ( 4776 ) 1 - 11 2020.9

Polysilane-Inserted Methylammonium Lead Iodide Perovskite Solar Cells Doped with Formamidinium and Potassium Reviewed

Takeo Oku, Satsuki Kandori, Masaya Taguchi, Atsushi Suzuki, Masanobu Okita, Satoshi Minami, Sakiko Fukunishi, Tomoharu Tachikawa

Energies 13 ( 4776 ) 1 - 11 2020.9

Photovoltaic Characteristics of CH3NH3PbI3 Perovskite Solar Cells Added with Ethylammonium Bromide and Formamidinium Iodide Reviewed

Nishi K., Oku T., Kishimoto T., Ueoka N., Suzuki A.

Coatings 10 ( 4 ) 2020.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

© 2020 by the authors. Photovoltaic characteristics of solar cell devices in which ethylammonium (EA) and formamidinium (FA) were added to CH3NH3PbI3 perovskite photoactive layers were investigated. The thin films for the devices were deposited by an ordinary spin-coating technique in ambient air, and the X-ray diffraction analysis revealed changes of the lattice constants, crystallite sizes and crystal orientations. By adding FA and EA, surface defects of the perovskite layer decreased, and the photoelectric parameters were improved. In addition, the highly (100) crystal orientations and device stabilities were improved by the EA and FA addition.

DOI： 10.3390/coatings10040410

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Photovoltaic Characteristics of CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> Perovskite Solar Cells Added with Ethylammonium Bromide and Formamidinium Iodide Reviewed

Nishi K, Oku T, Kishimoto T, Ueoka N, Suzuki A

Coatings 10 ( 4 ) 2020.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

DOI： 10.3390/coatings10040410

Electronic structures, spectroscopic properties, and thermodynamic characterization of sodium- or potassium-incorporated CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> by first-principles calculation Reviewed

Suzuki A., Miyamoto Y., Oku T.

Journal of Materials Science 2020.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Science

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Influence of alkali metals such as sodium (Na) and potassium (K) in methyl ammonium lead iodide CH3NH3PbI3 perovskite crystal on electronic structures, spectroscopic properties, and thermodynamic properties was investigated by first-principles calculation. Partial substitution of CH3NH3 with Na or K in the perovskite crystal generated 3s, 3p, 4s, and 4p orbitals of Na or K above conduction band, which promoted the charge transfer from the alkali metals to the conduction band, accelerating the carrier generation and diffusion related to the photovoltaic performances. The molar absorption coefficient and oscillation strength were increased by a slight deviation of the charge distribution near ligand in the coordination structure. The splitting of chemical shift of 127I-NMR in magnetic field was caused by a slight perturbation of the coordination structure with nuclear quadrupole interaction based on electronic field gradient. Decrease of the Gibbs free energy and entropy indicated the thermodynamic stabilization without scattering carrier diffusion as phonon effectiveness. The decrease of the entropy was based on a slight change of stretching vibration mode of Pb–I bond with vending mode of N–H and C–H bonds in the infrared and Raman spectra. The minor addition of 12.5% Na or K into the perovskite crystal will improve the photovoltaic properties, open voltage related to band gap, and short-circuit current density based on the carrier diffusion with phonon effectiveness.

DOI： 10.1007/s10853-020-04511-y

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Suzuki A, Miyamoto Y, Oku T

Journal of Materials Science 2020.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Science

DOI： 10.1007/s10853-020-04511-y

Effects of annealing temperature on decaphenylcyclopentasilane-inserted CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> perovskite solar cells Reviewed

Taguchi M., Suzuki A., Oku T., Ueoka N., Minami S., Okita M.

Chemical Physics Letters 737 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Physics Letters

© 2019 Elsevier B.V. Perovskite solar cells, in which decaphenylcyclopentasilane (DPPS) layers were formed on the surface of the CH3NH3PbI3 perovskite layer, were fabricated and characterized. The photovoltaic properties were improved by controlling the annealing temperature of the perovskite layer. For perovskite layers annealed at high temperatures of ~200 °C, the perovskite crystals were densely formed and the surface coverage of the perovskite layer was improved. The DPPS-laminated devices suppressed the formation of PbI2 crystals and the stability was improved by the DPPS layer.

DOI： 10.1016/j.cplett.2019.136822

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Effects of annealing temperature on decaphenylcyclopentasilane-inserted CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> perovskite solar cells Reviewed

Taguchi M, Suzuki A, Oku T, Ueoka N, Minami S, Okita M

Chemical Physics Letters 737 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Physics Letters

DOI： 10.1016/j.cplett.2019.136822

Fabrication and characterization of perovskite type solar cells using phthalocyanine complexes Reviewed

Suzuki A., Okumura H., Yamasaki Y., Oku T.

Applied Surface Science 488 586 - 592 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Applied Surface Science

© 2019 Elsevier B.V. Perovskite compound-based solar cells using metal free phthalocyanine, silicon phthalocyanine or germanium naphthalocyanine complexes were fabricated and characterized for improving the photovoltaic performance. Additive effects of metal free phthalocyanine, silicon phthalocyanine or germanium naphthalocyanine complexes into the methyl ammonium‑lead-halide perovskite layer on the photovoltaic properties were investigated. The slight addition of the silicon phthalocyanine into the perovskite layer caused suppression of defect and pinhole in the surface layer, which had the best photovoltaic performance. The phthalocyanine complexes play an important role for improving the crystal growth, carrier generation and diffusion without carrier recombination and trapping near the defect and pinhole in the perovskite layer.

DOI： 10.1016/j.apsusc.2019.05.305

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Fabrication and characterization of perovskite type solar cells using phthalocyanine complexes Reviewed

Suzuki A, Okumura H, Yamasaki Y, Oku T

Applied Surface Science 488 586 - 592 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Applied Surface Science

DOI： 10.1016/j.apsusc.2019.05.305

Fabrication and evaluation of K-doped MA<inf>0.8</inf>FA<inf>0.1</inf>K<inf>0.1</inf>PbI<inf>3</inf>(Cl) perovskite solar cells Reviewed

Machiba H., Oku T., Kishimoto T., Ueoka N., Suzuki A.

Chemical Physics Letters 730 117 - 123 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Physics Letters

© 2019 Elsevier B.V. Perovskite solutions that were doped with potassium (K) salts (CH3NH3)0.8(HC(NH2)2)0.1K0.1PbI3 (MA0.8FA0.1K0.1PbI3(Cl)) were used to fabricate perovskite solar cells. The addition of the K salts resulted in fine grained perovskite crystals that were separated by very small gaps. These materials were used to fabricate solar cells that improved short circuit current densities, which resulted in an enhanced conversion efficiency, compared with standard materials. The K occupied the (CH3NH3)/(HC(NH2) defects within the perovskite crystals, which caused the lattice constant to increase. Additionally, the presence of K in the perovskite solutions promoted the growth of grains within the perovskite crystals.

DOI： 10.1016/j.cplett.2019.05.050

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Fabrication and evaluation of K-doped MA<inf>0.8</inf>FA<inf>0.1</inf>K<inf>0.1</inf>PbI<inf>3</inf>(Cl) perovskite solar cells Reviewed

Machiba H, Oku T, Kishimoto T, Ueoka N, Suzuki A

Chemical Physics Letters 730 117 - 123 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Physics Letters

DOI： 10.1016/j.cplett.2019.05.050

First-principles calculation study of electronic structures of alkali metals (Li, K, Na and Rb)-incorporated formamidinium lead halide perovskite compounds Reviewed

A. Suzuki, T. Oku

Applied Surface Science 483 912 - 921 2019.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier Participation form：Joint(The main charge)

Electronic structures of alkali metals (Li, Na, K or Rb)-incorporated formamidinium lead halide perovskite compounds were investigated by first-principles calculation. The conduction band were supplied with electrons from energy levels at 2s, 3s, 4s and 5s orbital of alkali metal to energy levels at 6p orbital of Pb atom in the perovskite crystal. Deviation of charge distribution in the perovskite crystal promoted the photo-induced charge generation, electron correlation and electron-lattice interaction as phonon effectiveness. The chemical shifts of 127 I-NMR in the perovskite crystal were originated in a slight perturbation of the coordination structure with nuclear quadruple interaction based on the electric field gradient. The slight incorporation of alkali metal near the ligand structure decreased the enthalpy with the Gibbs free-energy by contribution of the entropy due to the P–I stretching vibration.

DOI： 10.1016/j.apsusc.2019.04.049

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First-principles calculation study of electronic structures of alkali metals (Li, K, Na and Rb)-incorporated formamidinium lead halide perovskite compounds Reviewed

A. Suzuki, T. Oku

Applied Surface Science 483 912 - 921 2019.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier

DOI： 10.1016/j.apsusc.2019.04.049

Effects of guanidinium addition to CH3NH3PbI3−xClx perovskite photovoltaic devices Reviewed International journal

Taku Kishimoto, Atsushi Suzuki, Naoki Ueoka, Takeo Oku

Journal of the Ceramic Society of Japan 127 ( 7 ) 491 - 497 2019.7

Effects of guanidinium addition to CH3NH3PbI3−xClx perovskite photovoltaic devices Reviewed

Taku Kishimoto, Atsushi Suzuki, Naoki Ueoka, Takeo Oku

Journal of the Ceramic Society of Japan 127 ( 7 ) 491 - 497 2019.7

Additive Effect of Formamidinium Chloride in Methylammonium Lead Halide Compound-Based Perovskite Solar Cells Reviewed

Suzuki A., Kato M., Ueoka N., Oku T.

Journal of Electronic Materials 48 ( 6 ) 3900 - 3907 2019.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Electronic Materials

© 2019, The Minerals, Metals & Materials Society. Perovskite compound-based solar cells using methylammonium lead iodine (CH3NH3I), lead iodine (PbI2) and formamidinium chloride (HC(NH2)2Cl: FACl) were fabricated and characterized for improving the photovoltaic performance. Additive effects of FACl into the methylammonium-lead-halide perovskite layer on the photovoltaic properties were investigated. The slight additive of FACl into the perovskite layer promoted the crystal nucleation and growth with the monodispersed domain as the surface morphologies, which improved the photovoltaic performance with external quantum efficiency over ultra-violet–visible–near infrared region. The photovoltaic performance was improved by the surface morphology with the monodispersed crystal growth in the homogenous phase for promoting the photo-induced carrier-generation and extension of the carrier diffusion with suppression of the carrier recombination and trapping near pinholes, defects, voids, cracks and interface between the domains in the perovskite layer.

DOI： 10.1007/s11664-019-07153-2

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Additive Effect of Formamidinium Chloride in Methylammonium Lead Halide Compound-Based Perovskite Solar Cells Reviewed

Suzuki A, Kato M, Ueoka N, Oku T

Journal of Electronic Materials 48 ( 6 ) 3900 - 3907 2019.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Electronic Materials

DOI： 10.1007/s11664-019-07153-2

Effects of KBr or KCl addition to CH3NH3PbI3(Cl) photovoltaic devices Reviewed International journal

Hayato Machiba, Takeo Oku and Atsushi Suzuki

AIP Conference Proceedings 2067 020009-1 - 7 2019.1

Fabrication and Characterization of Perovskite Solar Cells added with Zinc Phthalocyanine to Active Layer Reviewed International journal

Atsushi Suzuki, Yuto Hayashi, Yasuhiro Yamasaki and Takeo Oku

AIP Conference Proceedings 2067 020010-1 - 6 2019.1

Effectsof TiO2 nanoparticleswithdifferent sizes on the performance of CH3NH3PbI3-xClx solar cells Reviewed International journal

Naoki Ueoka, Takeo Oku, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, and Masanobu Okita

AIP Conference Proceedings 2067 020001-1 - 10 2019.1

Effects of poly(methyl methacrylate) addition to perovskite photovoltaic devices Reviewed International journal

Masaya Taguchi, Atsushi Suzuki, Naoki Ueoka, and Takeo Oku

AIP Conference Proceedings 2067 020018-1 - 8 2019.1

Fabrication and Characterization of Perovskite Solar Cells added with Zinc Phthalocyanine to Active Layer Reviewed

Atsushi Suzuki, Yuto Hayashi, Yasuhiro Yamasaki, Takeo Oku

AIP Conference Proceedings 2067 020010-1 - 6 2019.1

Effects of KBr or KCl addition to CH3NH3PbI3(Cl) photovoltaic devices Reviewed

Hayato Machiba, Takeo Oku, Atsushi Suzuki

AIP Conference Proceedings 2067 020009-1 - 7 2019.1

Effectsof TiO2 nanoparticleswithdifferent sizes on the performance of CH3NH3PbI3-xClx solar cells Reviewed

Naoki Ueoka, Takeo Oku, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, Masanobu Okita

AIP Conference Proceedings 2067 020001-1 - 10 2019.1

Effects of poly(methyl methacrylate) addition to perovskite photovoltaic devices Reviewed

Masaya Taguchi, Atsushi Suzuki, Naoki Ueoka, Takeo Oku

AIP Conference Proceedings 2067 020018-1 - 8 2019.1

Effects of Decaphenylcyclopentasilane Addition on Photovoltaic Properties of Perovskite Solar Cell Reviewed International journal

Masaya Taguchi, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, Satoshi Minami, Masanobu Okita

Coatings 8 461 2018.12

Effects of decaphenylcyclopentasilane addition on photovoltaic properties of perovskite solar cells Reviewed

Taguchi M., Suzuki A., Oku T., Fukunishi S., Minami S., Okita M.

Coatings 8 ( 12 ) 2018.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

© 2018 by the authors. Perovskite solar cells, in which decaphenylcyclopentasilane (DPPS) layers were formed on the surface of the perovskite layer, were fabricated, and the influence on photovoltaic characteristics was investigated. The devices were fabricated by a spin-coating technique, and the surface morphology and crystal structures were investigated by scanning electron microscopy and X-ray diffraction. By adding the DPPS, the fill factor and open circuit voltage were increased, and the photoelectric conversion efficiency was improved. A stability test in ambient air was carried out for seven weeks, and the photoelectric conversion efficiencies were remarkably improved for the devices with DPPS.

DOI： 10.3390/COATINGS8120461

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Effects of decaphenylcyclopentasilane addition on photovoltaic properties of perovskite solar cells Reviewed

Taguchi M, Suzuki A, Oku T, Fukunishi S, Minami S, Okita M

Coatings 8 ( 12 ) 461 2018.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

DOI： 10.3390/COATINGS8120461

Effects of decaphenylcyclopentasilane addition on photovoltaic properties of perovskite solar cells Reviewed

Taguchi M, Suzuki A, Oku T, Fukunishi S, Minami S, Okita M

Coatings 8 ( 12 ) 2018.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Coatings

DOI： 10.3390/COATINGS8120461

Effects of transition metals incorporated into perovskite crystals on the electronic structures and magnetic properties by first-principles calculation Reviewed

Suzuki A., Oku T.

Heliyon 4 ( 8 ) 2018.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Heliyon

© 2018 The Authors Additive effects of transition metals (M = Cr2+, Co2+, Cu2+and Y3+) on the electronic structures and magnetic properties of formamidinium lead halide perovskite compounds (FAPbI3, where FA = NH2CHNH2+) were investigated by first-principle calculation using density functional theory. In the case of Cr2+, Cu2+and Y3+-incorporated FAPbI3perovskite crystals, the electron density distribution of d-p hybrid orbital on the transition metal and iodine halogen-atoms were delocalized at frontier orbital. The total and partial density of state appeared the 3d-p hybrid orbital near the frontier orbital with narrowing band gap, yielding the wide broad absorption in the near-infrared region. The electronic correlation worked in between the localized spin on 3d orbital of the metal, and the itinerant carriers on the 5p orbital of the iodine halogen ligand and the 6p orbital of the lead atom in the perovskite crystal. The vibration behavior of the Raman and Infrared spectra were associated with change of polarization and slight distortion near the coordination structure. The considerable splitting of chemical shift of127I-NMR and207Pb-NMR in the Co2+and Cu2+-incorporated FAPbI3crystals were caused by crystal field splitting as Jahn-Teller effect with nearest-neighbor nuclear quadrupole interaction based on the charge distribution.

DOI： 10.1016/j.heliyon.2018.e00755

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Effects of transition metals incorporated into perovskite crystals on the electronic structures and magnetic properties by first-principles calculation Reviewed

Suzuki A, Oku T

Heliyon 4 ( 8 ) 2018.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Heliyon

DOI： 10.1016/j.heliyon.2018.e00755

Fabrication and characterization of perovskite solar cells added with MnCl2, YCl3 or poly(methyl methacrylate) Reviewed

Masaya Taguchi, Atsushi Suzuki, Hiroki Tanaka, Takeo Oku

AIP Conference Proceedings 1929 ( 020012 ) 1 - 8 2018.1

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Institute of Physics Inc.

Perovskite-type CH3NH3PbI3-based photovoltaic devices were fabricated and characterized. Effects of manganese (Mn), yttrium (Y) compounds addition into the perovskite crystal on the photovoltaic properties were investigated. Also, the effects of poly(methyl methacrylate) (PMMA) addition on perovskite layer on the photovoltaic properties were investigated. When 3 % MnCl2 was added, the short circuit current density and conversion efficiency were improved by promoting the crystal growth of perovskite phase. The photoelectric conversion efficiency for 0.9 mg mL-1 PMMA added was 7.36 %. Open circuit voltage and fill factor were improved by 5 % YCl3 addition.

DOI： 10.1063/1.5021925

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Rietveld refinement of the crystal structure of perovskite solar cells using CH3NH3PbI3 and other compounds Reviewed

Yuji Ando, Yuya Ohishi, Kohei Suzuki, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1929 ( 020003 ) 1 - 8 2018.1

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Institute of Physics Inc.

The crystal structures of perovskite thin films including CH3NH3PbI3, CH3NH3Pb1-xSbxI3, and CH3NH3PbI3-yCly in the solar cell configuration were studied by using Rietveld refinement. For the CH3NH3PbI3 and CH3NH3Pb1-xSbxI3 samples, satisfactory agreement with the measured profiles was obtained with a weighted profile R-factor (Rwp) of as low as 3%. It was shown that the site occupancy of methylammonium (MA) was decreased in the antimonized cell due to the compensation effect of an increased positive charge brought about by replacing Pb2+ with Sb3+. Photovoltaic measurements showed that the power conversion efficiency was enhanced by adding a small amount of Sb to the CH3NH3PbI3 cell, but it was monotonically decreased as the mole fraction of Sb exceeded 0.03. This variation of the conversion efficiency was considered as a result of suppressed crystallization of PbI2 and carrier recombination via MA vacancies in the antimonized cells. In the case of CH3NH3PbI2.88Cl0.12 sample, the agreement with the measured profile with an Rwp of as high as 7% suggested the co-existence of cubic and tetragonal phases in the chlorinated cell.

DOI： 10.1063/1.5021916

Scopus

Insertion effect of spin-coated films of C60-ethylenediamine adduct on organic thin-film solar cells Reviewed

Atsutaka Yamada, Daisuke Izumoto, Tsuyoshi Akiyama, Katsuhiko Fujita, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1929 ( 020020 ) 1 - 5 2018.1

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Institute of Physics Inc.

C60-ethylanediamine adduct particle (C60P) were prepared by simply mixing of C60 and ethylenediamine (EDA) in toluene. C60P was dissolved into EDA to obtain C60P-EDA. C60P-EDA can be diluted by ethanol, 2-methoxyethanol or water. Thin films of C60P-EDA were prepared from these diluted solutions of C60P-EDA by spin-coating. Such thin-films were used as a part of organic thin-film solar cells.

DOI： 10.1063/1.5021933

Scopus

Fabrication and characterization of rubidium/formamidinium-incorporated methylammonium-lead-halide perovskite solar cells Reviewed

Masataka Kato, Atsushi Suzuki, Yuya Ohishi, Hiroki Tanaka, Takeo Oku

AIP Conference Proceedings 1929 ( 020015 ) 1 - 7 2018.1

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Institute of Physics Inc.

Fabrication and characterization of perovskite solar cells using mesoporous TiO2 as an electron transporting layer and 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene as a hole-transporting layer were performed for improving the photovoltaic performance. Additive effects of formamidinium (FA), rubidium (Rb), chlorine (Cl) and bromine (Br) into the methylammonium-lead-halide perovskite crystal on the photovoltaic properties and microstructures were investigated. The photovoltaic parameters of short-circuit current density, conversion efficiency, the surface morphology and domain in the perovskite crystal were characterized. The slight addition of FACl and RbBr to the CH3NH3PbI3 crystal provided homogeneous microstructures with the dispersed crystal domains, which improved the photovoltaic performance. The excess addition of Cl to the perovskite crystal caused nanorod-like crystals, which degraded the photovoltaic performance.

DOI： 10.1063/1.5021928

Scopus

Effects of CsBr addition on the performance of CH3NH3PbI3- xClx-based solar cells Reviewed

Naoki Ueoka, Takeo Oku, Yuya Ohishi, Hiroki Tanaka, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, Shinichiro Tsukada

AIP Conference Proceedings 1929 ( 020026 ) 1 - 8 2018.1

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Institute of Physics Inc.

Perovskite-type photovoltaic devices were prepared by a spin-coating method using a precursor solution of CH3NH3I and lead(II) chloride in N,N-dimethylformamide. Effects of cesium bromide (CsBr) addition on the photovoltaic properties and microstructures of the perovskite phase were investigated. The fill factor was increased by adding the CsBr to the CH3NH3PbI3-xClx precursor solution, which resulted in increase of the conversion efficiency. The crystallinity of the CH3NH3PbI3-xClx perovskite phase was also improved by adding the CsBr to the H3NH3PbI3-xClx precursor solution.

DOI： 10.1063/1.5021939

Scopus

Fabrication and characterization of perovskite solar cells added with MnCl2, YCl3 or poly(methyl methacrylate) Reviewed International journal

Masaya Taguchi, Atsushi Suzuki, Hiroki Tanaka, and Takeo Oku

AIP Conference Proceedings 1929 ( 020012 ) 1 - 8 2018.1

Insertion effect of spin-coated films of C60-ethylenediamine adduct on organic thin-film solar cells Reviewed International journal

22) Atsutaka Yamada, Daisuke Izumoto, Tsuyoshi Akiyama, Katsuhiko Fujita, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1929 ( 020020 ) 1 - 5 2018.1

Rietveld refinement of the crystal structure of perovskite solar cells using CH3NH3PbI3 and other compounds Reviewed International journal

Yuji Ando, Yuya Ohishi, Kohei Suzuki, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1929 ( 020003 ) 1 - 8 2018.1

Effects of CsBr addition on the performance of CH3NH3PbI3-xClx-based solar cells Reviewed International journal

20) Naoki Ueoka, Takeo Oku, Yuya Ohishi, Hiroki Tanaka, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, and Shinichiro Tsukada

AIP Conference Proceedings 1929 ( 020026 ) 1 - 8 2018.1

Fabrication and characterization of rubidium/formamidinium-incorporated methylammonium-lead-halide perovskite solar cells Reviewed International journal

Masataka Kato, Atsushi Suzuki, Yuya Ohishi, Hiroki Tanaka, and Takeo Oku

AIP Conference Proceedings 1929 ( 020015 ) 1 - 7 2018.1

First-principles calculation study of electronic structures and magnetic properties of Mn-doped perovskite crystals for solar cell applications Reviewed International journal

Atsushi Suzuki and Takeo Oku

Jpn. J. Appl. Phys. 57 ( 02CE04 ) 1 - 7 2017.12

First-principles calculation study of electronic structures and magnetic properties of Mn-doped perovskite crystals for solar cell applications Reviewed

Atsushi Suzuki, Takeo Oku

Jpn. J. Appl. Phys. 57 ( 02CE04 ) 1 - 7 2017.12

Fabrication and characterization of CH3NH3(Cs)Pb(Sn)I3(Cl) perovskite solar cells with TiO2 nanoparticle layers Reviewed International journal

Naoki Ueoka, Takeo Oku, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, and Shinsuke Miyauchi

Japanese Journal of Applied Physics 57 ( 02CE03 ) 1 - 7 2017.12

Fabrication and characterization of CH3NH3(Cs)Pb(Sn)I3(Cl) perovskite solar cells with TiO2 nanoparticle layers Reviewed

Naoki Ueoka, Takeo Oku, Atsushi Suzuki, Hiroki Sakamoto, Masahiro Yamada, Satoshi Minami, Shinsuke Miyauchi

Japanese Journal of Applied Physics 57 ( 02CE03 ) 1 - 7 2017.12

Effects of Metal Phthalocyanines as Hole-transporting Layers of Perovskite-based Solar Cells Reviewed International journal

Atsushi Suzuki, Haruka Ueda, Yuki Okada, Yuya Ohishi, Yasuhiro Yamasaki, Takeo Oku

Chemical and Materials Engineering 5 ( 2 ) 34 - 42 2017.5

Effects of Metal Phthalocyanines as Hole-transporting Layers of Perovskite-based Solar Cells Reviewed

Atsushi Suzuki, Haruka Ueda, Yuki Okada, Yuya Ohishi, Yasuhiro Yamasaki, Takeo Oku

Chemical and Materials Engineering 5 ( 2 ) 34 - 42 2017.5

Effects of CsI and/or SnBr2 Additions to CH3NH3PbI3 Perovskite Solar Cells Reviewed International journal

Naoki Ueoka, Takeo Oku, Atsushi Suzuki

Nanoscience and Nanoengineering 5 ( 3 ) 25 - 30 2017.5

Effects of CsI and/or SnBr2 Additions to CH3NH3PbI3 Perovskite Solar Cells Reviewed

Naoki Ueoka, Takeo Oku, Atsushi Suzuki

Nanoscience and Nanoengineering 5 ( 3 ) 25 - 30 2017.5

Effects of NH4Cl addition to perovskite CH3NH3PbI3 photovoltaic device Reviewed International journal

Takeo OKU, Yuya OHISHI, Atsushi SUZUKI and Yuzuru MIYAZAWA

Journal of the Ceramic Society of Japan 125 ( 4 ) 303 - 307 2017.4

Effects of Metal Phthalocyanines as Hole-transporting Layers of Perovskite-based Solar Cells Reviewed International journal

Atsushi Suzuki, Haruka Ueda, Yuki Okada, Yuya Ohishi, Yasuhiro Yamasaki, Takeo Oku

Chemical and Materials Engineering 5 ( 2 ) 34 - 42 2017.4

Effects of Metal Phthalocyanines as Hole-transporting Layers of Perovskite-based Solar Cells Reviewed

Atsushi Suzuki, Haruka Ueda, Yuki Okada, Yuya Ohishi, Yasuhiro Yamasaki, Takeo Oku

Chemical and Materials Engineering 5 ( 2 ) 34 - 42 2017.4

Effects of NH4Cl addition to perovskite CH3NH3PbI3 photovoltaic devices Reviewed

Takeo Oku, Yuya Ohishi, Atsushi Suzuki, Yuzuru Miyazawa

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 125 ( 4 ) 303 - 307 2017.4

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Effects of NH4Cl addition to perovskite CH3NH3PbI3 precursor solutions on photovoltaic properties were investigated. TiO2/CH3NH3PbI3(Cl)-based photovoltaic devices were fabricated by a spin-coating technique, and the microstructures of the devices were investigated by X-ray diffraction and scanning electron microscopy. Current density-voltage characteristics were improved by a small amount of Cl-doping, which resulted in improvement of the efficiencies of the devices. The structure analysis indicated formation of a homogeneous microstructure by NH4Cl addition to the perovskite phase, and formation of PbI2 was suppressed by the NH4Cl addition. (C) 2017 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.16279

Web of Science

Effects of polysilane-doped spiro-OMeTAD hole transport layers on photovoltaic properties Reviewed

Shirahata Y., Yamomoto Y., Suzuki A., Oku T., Fukunishi S., Kohno K.

Physica Status Solidi (A) Applications and Materials Science 214 ( 3 ) 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Physica Status Solidi (A) Applications and Materials Science

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Effects of polysilane-doped 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamino)-9,9′-spirobifluorene (spiro-OMeTAD) hole transport layers on photovoltaic properties were investigated by measuring current density–voltage characteristics and incident photon-to-current conversion efficiency of CH3NH3PbI3-based photovoltaic devices. Three kinds of polysilanes were used as the dopants. Due to the polysilane doping, conversion efficiencies of the CH3NH3PbI3devices using the polysilane-doped hole transport layers were improved. Microstructures of the CH3NH3PbI3devices were also investigated. Based on the results of the microstructure analysis, impact of silicon in the polysilanes doped into spiro-OMeTAD layer on photovoltaic properties were discussed.

DOI： 10.1002/pssa.201600591

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Effects of polysilane-doped spiro-OMeTAD hole transport layers on photovoltaic properties Reviewed

Yasuhiro Shirahata, Yuki Yamomoto, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, Kazufumi Kohno

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE 214 ( 3 ) 1600591 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Effects of polysilane-doped 2,2,7,7-tetrakis-(N,N-di-p-methoxyphenylamino)-9,9-spirobifluorene (spiro-OMeTAD) hole transport layers on photovoltaic properties were investigated by measuring current density-voltage characteristics and incident photon-to-current conversion efficiency of CH3NH3PbI3-based photovoltaic devices. Three kinds of polysilanes were used as the dopants. Due to the polysilane doping, conversion efficiencies of the CH3NH3PbI3 devices using the polysilane-doped hole transport layers were improved. Microstructures of the CH3NH3PbI3 devices were also investigated. Based on the results of the microstructure analysis, impact of silicon in the polysilanes doped into spiro-OMeTAD layer on photovoltaic properties were discussed.

DOI： 10.1002/pssa.201600591

Web of Science

Effects of polysilane-doped spiro-OMeTAD hole transport layers on photovoltaic properties Reviewed

Yasuhiro Shirahata, Yuki Yamomoto, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, Kazufumi Kohno

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE 214 ( 3 ) 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

DOI： 10.1002/pssa.201600591

Web of Science

Fabrication and electrochemical properties of insoluble fullerene-diamine adduct thin-films as buffer layer by alternate immersion process Reviewed International journal

Jo Saito, Tsuyoshi Akiyama, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1807 020017 2017.1

Effects of halogen doping on the photovoltaic properties of HC(NH2)2PbI3 perovskite solar cells Reviewed

Yuri Umemoto, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1807 020011 2017.1

Fabrication and characterization of perovskite photovoltaic devices with TiO2 nanoparticle layers Reviewed

Takeo Oku, Naoki Ueoka, Kohei Suzuki, Atsushi Suzuki, Masahiro Yamada, Hiroki Sakamoto

AIP Conference Proceedings 1807 020014 2017.1

Fabrication and characterization of perovskite based solar cells using phthalocyanine and naphthalocyanine as hole-transporting layer Reviewed International journal

Yuki Okada, Atsushi Suzuki, Yasuhiro Yamasaki, Takeo Oku

AIP Conference Proceedings 1807 020015 2017.1

Fabrication and characterization of CH3NH3(Cs)Pb(Sn)I3(Br) perovskite solar cells Reviewed International journal

Naoki Ueoka, Yuya Ohishi, Yasuhiro Shirahata, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1807 020009 2017.1

Doping effects of transition metal elements to titanium dioxide for perovskite solar cells Reviewed International journal

Jo Saito, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

AIP Conference Proceedings 020010 2017.1

Effects of SbBr3 addition to CH3NH3PbI3 solar cells Reviewed International journal

Takeo Oku, Yuya Ohishi, Atsushi Suzuki

AIP Conference Proceedings 1807 ( 020007 ) 1 - 5 2017.1

Doping effects of transition metal elements to titanium dioxide for perovskite solar cells Reviewed

Jo Saito, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

AIP Conference Proceedings 020010 2017.1

Fabrication and Characterization of PCBM: P3HT-based Thin-film Organic Solar Cells with Zinc Phthalocyanine and 1,8-Diiodooctane Reviewed International journal

Haruto Maruhashi, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Chemical and Materials Engineering 5 ( 1 ) 1 - 7 2017.1

Structures and photovoltaic properties of element-doped CH<inf>3</inf>NH<inf>3</inf>PBI<inf>3</inf>perovskite solar cells Reviewed

Oku T., Zushi M., Suzuki K., Ohishi Y., Matsumoto T., Iwata T., Ueoka N., Suzuki A.

Organic Solar Cells: Advances in Research and Applications 51 - 89 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Organic Solar Cells: Advances in Research and Applications

© 2017 Nova Science Publishers, Inc. CH3NH3PbI3-based perovskite solar cells were fabricated and characterized. Metal doping and halogen doping to the perovskite and TiO2 were investigated. Increases in the efficiencies of the devices were observed, which was due to the structural change of the perovskite compound layers. X-ray diffraction analysis and transmission electron microscopy were used for investigation of the devices. The structure analysis by them showed structural transformation of the crystal structure of the perovskite, which indicated that a cubic-tetragonal crystal system depended on the annealing condition and element-doping.

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Fabrication and Characterization of PCBM: P3HT-based Thin-film Organic Solar Cells with Zinc Phthalocyanine and 1,8-Diiodooctane Reviewed

Haruto Maruhashi, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Chemical and Materials Engineering 5 ( 1 ) 1 - 7 2017.1

Structures and photovoltaic properties of element-doped CH<inf>3</inf>NH<inf>3</inf>PBI<inf>3</inf>perovskite solar cells Reviewed

Oku T, Zushi M, Suzuki K, Ohishi Y, Matsumoto T, Iwata T, Ueoka N, Suzuki A

Organic Solar Cells: Advances in Research and Applications 51 - 89 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Organic Solar Cells: Advances in Research and Applications

Fabrication and characterization of perovskite based solar cells using phthalocyanine and naphthalocyanine as hole-transporting layer Reviewed

Yuki Okada, Atsushi Suzuki, Yasuhiro Yamasaki, Takeo Oku

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 020015 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Organic-inorganic hybrid heterojunction solar cells containing CH3NH3PbI3 perovskite compound were fabricated using TiO2 as an electronic transporting layer and spirobifluorence as a hole-transporting layer. The purpose of the present study is to investigate a role of the hole-transporting layer on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells. The X-ray diffraction identified crystal structures of the perovskite layer in the solar cells. Optical microscopy showed different surface morphologies, and the perovskite structures on the TiO2 mesoporous structure depended on addition of phthalocyanine into the hole-transporting layer. The photovoltaic properties and holetransporting behavior was depending on carrier mobility, electron structures of the perovskite crystal and band gaps related with the photovoltaic parameters. Energy diagram and photovoltaic mechanism of the perovskite solar cells using holetransporting layers were discussed by experimental results. Perovskite based solar cells using phthalocyanines as holetransporting layers have advantages to provide a high photovoltaic performance with a wide region of optical absorption.

DOI： 10.1063/1.4974797

Web of Science

Fabrication and electrochemical properties of insoluble fullerene-diamine adduct thin-films as buffer layer by alternate immersion process Reviewed

Jo Saito, Tsuyoshi Akiyama, Atsushi Suzuki, Takeo Oku

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 020017 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Insoluble fullerene-diamine adduct thin-films consisting of C-60 and 1,2-diaminoethane were easily fabricated on an electrode by an alternate immersion process. Formation of the C-60 -diamine adduct films were confirmed using transmission absorption spectroscopy and atomic force microscopy. An inverted-type organic solar cells were fabricated by using the C-60 -diamine adduct film as the electron transport layer. The resultant photoelectric conversation performance of the solar cells suggested that photocurrent is generated via the photoexcitation of polythiophene. The result suggests that the present insoluble fullerene-diamine adduct films worked as buffer layer for organic thin-film solar cells.

DOI： 10.1063/1.4974799

Web of Science

Fabrication and Characterization of Perovskite Photovoltaic Devices with TiO2 Nanoparticle Layers Reviewed

Takeo Oku, Naoki Ueoka, Kohei Suzuki, Atsushi Suzuki, Masahiro Yamada, Hiroki Sakamoto, Satoshi Minami, Sakiko Fukunishi, Kazufumi Kohno, Shinsuke Miyauchi

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 020014 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

TiO2/CH3NH3PbI3-based photovoltaic devices were fabricated by a spin-coating method using mixture solutions with TiO2 nanoparticles. Compact TiO2 layers were prepared from titanium diisopropoxide bis(acetyl acetonate) and TiO2 nanoparticles with different particle sizes. The performance of the photovoltaic devices was improved by sequential deposition of the TiO2 layers, which resulted in microstructural change of the perovskite layers.

DOI： 10.1063/1.4974796

Web of Science

Effects of halogen doping on the photovoltaic properties of HC(NH2)(2)PbI3 perovskite solar cells Reviewed

Yuri Umemoto, Atsushi Suzuki, Takeo Oku

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 020011 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Fabrication and characterization of perovskite-based solar cell using TiO2 as an electron transporting layer and 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino) -9,9'-spirobifluorene as a hole transporting layer (HTL) have been performed for improving the photovoltaic performance. The purpose of the present study is to investigate a role of halogen doping using iodine, bromine and chlorine compounds on the photovoltaic performance such as short-circuit current density, open-circuit voltage, conversion efficiency and microstructures of HC(NH2)(2)PbI3-x-yBrxCly perovskite solar cells. The photovoltaic properties were investigated by current-voltage curves under light irradiation, incident photon to current conversion efficiency, X-ray diffraction and optical microscopy. The photovoltaic performance and optical properties were influenced by halogen addition into the perovskite crystal structure

DOI： 10.1063/1.4974793

Web of Science

Fabrication and characterization of CH3NH3(Cs)Pb(Sn)I-3(Br) perovskite solar cells Reviewed

Naoki Ueoka, Yuya Ohishi, Yasuhiro Shirahata, Atsushi Suzuki, Takeo Oku

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 020009 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Perovskite-type CH3NH3(MA)PbI3-based photovoltaic devices were fabricated and characterized. Doping effects of cesium iodide (CsI), cesium bromide (CsBr) and tin bromide (SnBr2) on the photovoltaic properties and surface microstructures of the perovskite phase were investigated. Short-circuit current densities, open-circuit voltages and fill factors increased by CsI and SnBr2 addition. The surface coverage of the perovskite crystals was also improved by SnBr2 doping, which resulted in improvement of the fill factor. The cell prepared by a starting composition of MA(0.95)Cs(0.05)Pb(0.95)Sn(0.05)I(2.90)Br(0.10) showed the best photovoltaic performance in the present work.

DOI： 10.1063/1.4974791

Web of Science

Effects of SbBr3 Addition to CH3NH3PbI3 Solar Cells Reviewed

Takeo Oku, Yuya Ohishi, Atsushi Suzuki

IRAGO CONFERENCE 2016: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1807 ( 020007 ) 1 - 5 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

TiO2/CH3NH3Pb1-xSbxI3-2xBr3x-based photovoltaic devices were fabricated, and effects of SbBr3 addition to CH3NH3PbI3 precursor solutions on the photovoltaic properties were investigated. The short-circuit current densities and photoconversion efficiencies were improved by adding a small amount of SbBr3 to the perovskite phase, which would be due to a doping effect of Sb or Br atoms at the Pb or I sites.

DOI： 10.1063/1.4974789

Web of Science

Effects of polysilane-doped spiro-OMeTAD hole transport layers on photovoltaic properties Reviewed International journal

Yasuhiro Shirahata, Yuki Yamomoto, Atsushi Suzuki, Takeo Oku, Sakiko Fukunishi, and Kazufumi Kohno

Phys. Status Solidi A 1600591 2016.11

Effects of central metal on electronic structure, magnetic properties, infrared and Raman spectra of double-decker phthalocyanine Reviewed International journal

Atsushi Suzuki, Takeo Oku

Applied Surface Science 380 127 - 134 2016.9

Effects of central metal on electronic structure, magnetic properties, infrared and Raman spectra of double-decker phthalocyanine Reviewed

Atsushi Suzuki, Takeo Oku

APPLIED SURFACE SCIENCE 380 127 - 134 2016.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The effects of the central metal in double-decker metal phthalocyanine on the electronic structure, magnetic properties, and infrared and Raman spectra of the complex were investigated. Electron density distributions were delocalized on the phthalocyanine rings. The narrow energy gap and infrared peaks observed in the ultra-violet-visible-near infrared spectra of the systems were attributed to phthalocyanine ring-ring interactions the between overlapping pi-orbitals on each ring. The chemical shift behavior of the phthalocyanine rings was separated by the deformation of their structure owing to nuclear magnetic interaction of the nuclear quadrupole interaction as determined by the electronic field gradient and asymmetric parameters. The magnetic parameters of principle g-tensors were dependent on the perturbation of the crystal field by the hybridization of the d-spin in the central metal conjugated with nitrogen ligands. In the case of the vanadyl system, the IR vibration modes were shifted by the soft vibration mode for resolving the symmetrical structure. Inactive Raman vibration modes arose from no-polarization on the phthalocyanine rings. Double-decker metal phthalocyanines have great advantages for the control of the magnetic mechanism for quantum spin entanglement in the relaxation process. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.apsusc.2016.02.026

Web of Science

Effects of Cl Addition to Sb-Doped Perovskite-Type CH3NH3PbI3 Photovoltaic Devices Reviewed International journal

Takeo Oku, Yuya Ohishi, Atsushi Suzuki and Yuzuru Miyazawa

Metals 6 ( 7 ) 147-1 - 147-3 2016.6

Effects of Cl Addition to Sb-Doped Perovskite-Type CH3NH3PbI3 Photovoltaic Devices Reviewed

Takeo Oku, Yuya Ohishi, Atsushi Suzuki, Yuzuru Miyazawa

Metals 6 ( 7 ) 147-1 - 147-3 2016.6

Fabrication and characterization of bismuth ferrite as an electron transport layer in perovskite photovoltaic devices Reviewed International journal

Yasuhiro SHIRAHATA, Atsushi SUZUKI, Takeo OKU

Journal of the Ceramic Society of Japan 124 ( 5 ) 602 - 605 2016.5

Fabrication and Characterization of CH3NH3PbI3-x-yBrxCly Perovskite Solar Cells Reviewed International journal

Atsushi Suzuki, Hiroshi Okada and Takeo Oku

Energies 9 ( 5 ) 376-1 - 376-11 2016.5

Fabrication and Characterization of CH3NH3PbI3-x-yBrxCly Perovskite Solar Cells Reviewed

Atsushi Suzuki, Hiroshi Okada, Takeo Oku

Energies 9 ( 5 ) 376-1 - 376-11 2016.5

Fabrication and characterization of bismuth ferrite as an electron transport layer in perovskite photovoltaic devices Reviewed

Yasuhiro Shirahata, Atsushi Suzuki, Takeo Oku

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 124 ( 5 ) 602 - 605 2016.5

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

BiFeO3 thin films were fabricated by a simple spin-coating method as an electron transport layer in CH3NH3PbI3-based photovoltaic devices. Single-phase BiFeO3 was obtained, which was confirmed by X-ray diffraction. To characterize photovoltaic properties, BiFeO3/CH3NH3PbI3-based photovoltaic devices were fabricated by different preparation steps for CH3NH3PbI3 layer, and current density-voltage characteristics of the photovoltaic devices showed rectifying behaviors. Comparing with the BiFeO3/CH3NH3PbI3 photovoltaic device fabricated by a 1-step method, the conversion efficiency of the device fabricated by a 2-step method was improved. Bandgaps of the BiFeO3 and CH3NH3PbI3 layers were also determined from optical absorption measurements. (C) 2016 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.15322

Web of Science

Electronic structures and magnetic/optical properties of metal phthalocyanine complexes Reviewed International journal

Shintaro Baba、Atsushi Suzuki、Takeo Oku

AIP Conference Proceedings 1709 020012-1 - 020012-8 2016.4

Microstructures and properties of hybrid solar cells Reviewed International journal

Kohei Suzuki、Atsushi Suzuki、Masahito Zushi、Takeo Oku

AIP Conference Proceedings 1649 96 - 101 2016.4

Fabrication and characterization of photovoltaic devices based on perovskite compounds with TiO2 nanoparticles Reviewed International journal

Masato Kanayama、Takeo Oku、Atsushi Suzuki、Masahiro Yamada、Sakiko Fukunishi、Kazufumi Kohno、Hiroki Sakamoto　

AIP Conference Proceedings 1649 84 - 88 2016.4

Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine Reviewed International journal

Haruto Maruhashi、Takeo Oku、Atsushi Suzuki、Tsuyoshi Akiyama、Yasuhiro Yamasaki

AIP Conference Proceedings 1649 89 - 95 2016.4

Fabrication and characterization of perovskite-type solar cells with Nb-doped TiO2 layers Reviewed International journal

Jo Saito、Takeo Oku、Atsushi Suzuki、Tsuyoshi Akiyama

AIP Conference Proceedings 1709 020027-1 - 020027-7 2016.4

Fabrication and characterization of perovskite-based CH3NH3Pb1-xGexI3, CH3NH3Pb1-xTlxI3 and CH3NH3Pb1-xInxI3 photovoltaic devices Reviewed International journal

Yuya Ohishi、Takeo Oku、Atsushi Suzuki

AIP Conference Proceedings 1709 020020-1 - 020020-8 2016.4

Low temperature fabrication of perovskite solar cells with TiO2 nanoparticle layers Reviewed International journal

Masato Kanayama、Takeo Oku、Atsushi Suzuki、Masahiro Yamada、Hiroki Sakamoto、Satoshi Minami、Kazufumi Kohno

AIP Conference Proceedings 1709 020019-1 - 020019-7 2016.4

Fabrication and photovoltaic properties of ZnO nanorods/perovskite solar cells Reviewed International journal

Yasuhiro Shirahata、Kohei Tanaike、Tsuyoshi Akiyama、Kazuya Fujimoto、Atsushi Suzuki、Jeyadevan Balachandran、Takeo Oku　

AIP Conference Proceedings 1709 020018-1 - 020018-9 2016.4

Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells Reviewed International journal

Atsushi Suzuki、Hiroshi Okada、Takeo Oku

AIP Conference Proceedings 1709 020022-1 - 020022-8 2016.4

Fabrication and photovoltaic properties of ZnO nanorods/perovskite solar cells Reviewed

Yasuhiro Shirahata, Kohei Tanaike, Tsuyoshi Akiyama, Kazuya Fujimoto, Atsushi Suzuki, Jeyadevan Balachandran, Takeo Oku

AIP Conference Proceedings 1709 020018-1 - 020018-9 2016.4

Electronic structures and magnetic/optical properties of metal phthalocyanine complexes Reviewed

Shintaro Baba, Atsushi Suzuki, Takeo Oku

AIP Conference Proceedings 1709 020012-1 - 020012-8 2016.4

Effects of chlorine addition to perovskite-type CH3NH3PbI3 photovoltaic devices Reviewed International journal

Takeo Oku、Kohei Suzuki、Atsushi Suzuki

Journal of the Ceramic Society of Japan 124 ( 3 ) 234 - 238 2016.3

Effects of chlorine addition to perovskite-type CH3NH3PbI3 photovoltaic devices Reviewed

Takeo Oku, Kohei Suzuki, Atsushi Suzuki

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 124 ( 3 ) 234 - 238 2016.3

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Effects of PbCl2 addition to perovskite CH3NH3PbI3 precursor solutions on the photovoltaic properties were investigated. TiO2/CH3NH3PbI3-xClx-based photovoltaic devices were fabricated, and the microstructures of the devices were investigated by X- ray diffraction. The structure analysis indicated phase transformation of the perovskite structure from cubic to tetragonal system by chlorine (Cl)-doping. External and internal quantum efficiencies were improved by a small amount of Cl- doping, which resulted in improvement of the efficiencies of the devices. This would be due to preservation of the cubic CH3NH3PbI3-xClx structure, and to expansion of energy gap and diffusion length of exitons by Cl-doping at the iodine sites. (C) 2016 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.15250

Web of Science

Effects of Antimony Addition to Perovskite-type CH3NH3PbI3 Photovoltaic Devices Reviewed International journal

Takeo Oku、Yuya Ohishi、Atsushi Suzuki

Chemistry Letters 45 ( 2 ) 134 - 136 2016.2

Effects of Antimony Addition to Perovskite-type CH3NH3PbI3 Photovoltaic Devices Reviewed

Takeo Oku, Yuya Ohishi, Atsushi Suzuki

CHEMISTRY LETTERS 45 ( 2 ) 134 - 136 2016.2

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Effects of SbI3 addition to CH3NH3PbI3 precursor solutions on the photovoltaic properties were investigated. TiO2/CH3NH3Pb1-xSbxI3-based photovoltaic devices were fabricated in air, and formation of a perovskite-type structure was confirmed by X-ray diffraction. The conversion efficiencies were improved by adding a small amount of Sb, and formation of PbI2 was suppressed by the Sb addition.

DOI： 10.1246/cl.150984

Web of Science

Fabrication and characterization of perovskite-based CH3NH3Pb1-xGexI3, CH(3)NH(3)Pb(1-x)TlxI(3) and CH3NH3Pb1-xInxI3 photovoltaic devices Reviewed

Yuya Ohishi, Takeo Oku, Atsushi Suzuki

IRAGO CONFERENCE 2015: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1709 020020-1 - 020020-8 2016

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Perovskite-type CH3NH3PbI3-based photovoltaic devices were fabricated and characterized. Doping effects of thallium (Tl), indium (In), or germanium (Ge) element on the photovoltaic properties and surface structures of the perovskite phase were investigated. The open circuit voltage increased by Ge addition, and fill factors were improved by adding a small amount of Ge, Tl or In. In addition, the wavelength range of incident photon conversion efficiencies was expanded by the Tl addition.

DOI： 10.1063/1.4941219

Web of Science

Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells Reviewed

Atsushi Suzuki, Hiroshi Okada, Takeo Oku

IRAGO CONFERENCE 2015: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1709 020022-1 - 020022-8 2016

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Organic-inorganic hybrid heterojunction solar cells containing CH3NH3PbI3 perovskite compound were fabricated using mesoporous TiO2 as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH3NH3PbI3 perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO2 mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of V-oc, J(sc) and eta. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results.

DOI： 10.1063/1.4941221

Web of Science

Low Temperature Fabrication of Perovskite Solar Cells with TiO2 Nanoparticle Layers Reviewed

Masato Kanayama, Takeo Oku, Atsushi Suzuki, Masahiro Yamada, Hiroki Sakamoto, Satoshi Minami, Kazufumi Kohno

IRAGO CONFERENCE 2015: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1709 020019-1 - 020019-7 2016

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

TiO2/CH3NH3PbI3-based photovoltaic devices were fabricated by a spin-coating method using a mixture solution. TiO2 require high-temperature processing to achieve suitably high carrier mobility. TiO2 electron transport layers and TiO2 scaffold layers for the perovskite were fabricated from TiO2 nanoparticles with different grain sizes. The photovoltaic properties and microstructures of solar cells were characterized. Nanoparticle sizes of these TiO2 were 23 nm and 3 nm and the performance of solar cells was improved by combination of two TiO2 nanoparticles

DOI： 10.1063/1.4941218

Web of Science

Fabrication and characterization of perovskite-type solar cells with Nb-doped TiO2 layers Reviewed

Jo Saito, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama

IRAGO CONFERENCE 2015: 360 DEGREE OUTLOOK ON CRITICAL SCIENTIFIC AND TECHNOLOGICAL CHALLENGES FOR A SUSTAINABLE SOCIETY 1709 020027-1 - 020027-7 2016

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Organic-inorganic hybrid heterojunction solar cells containing perovskite CH3NH3PbI3 using Nb-doped TiO2 as an electron-transporting layer were fabricated and characterized. Nb-doped TiO2 layer showed an improvement of the short-circuit current density and power conversion efficiency using Ti0.95Nb0.05O2.

DOI： 10.1063/1.4941226

Web of Science

Fabrication and Characterization of a Perovskite-Type Solar Cell with a Substrate Size of 70 mm Reviewed

Takeo Oku, Taisuke Matsumoto, Atsushi Suzuki, Kohei Suzuki

COATINGS 5 ( 4 ) 646 - 655 2015.12

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG

A perovskite-type solar cell with a substrate size of 70 mm x 70 mm was fabricated by a simple spin-coating method using a mixed solution. The photovoltaic properties of the TiO2/CH3NH3PbI3-based photovoltaic devices were investigated by current density-voltage characteristic and incident photon to current conversion efficiency measurements. Their short-circuit current densities were almost constant over a large area. The photoconversion efficiency was influenced by the open-circuit voltage, which depended on the distance from the center of the cell.

DOI： 10.3390/coatings5040646

Web of Science

Effects of hole-transporting layers of perovskite-based solar cells Reviewed International journal

Atsushi Suzuki, Tomoyasu Kida, Tatsuru Takagi and Takeo Oku

Japanese Journal of Applied Physics 55 02BF01-1 - 02BF01-5 2015.11

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Publishing

Fabrication and characterization of the photovoltaic and optical properties, and microstructure of perovskite-based solar cells with lead phthalocyanine (PbPc), zinc phthalocyanine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and copper(I)thiocyanate as hole-transporting layers were investigated. X-ray diffraction analysis and energy-dispersive X-ray spectroscopy were used to identify surface morphologies of the crystal structure and the elemental composition. Introducing PbPc into perovskite solar cells extended the retaining period of photovoltaic activity and performance. The effects of the hole-transporting layer on incident photon-to-current efficiency were investigated. The energy diagram and photovoltaic mechanism of the perovskite solar cells with the hole-transporting layer are discussed.

Effects of hole-transporting layers of perovskite-based solar cells Reviewed

Atsushi Suzuki, Tomoyasu Kida, Tatsuru Takagi, Takeo Oku

Japanese Journal of Applied Physics 55 02BF01-1 - 02BF01-5 2015.11

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Publishing

Fabrication and Characterization of a Perovskite-Type Solar Cell with a Substrate Size of 70 mm Reviewed International journal

Takeo Oku、Taisuke Matsumoto、Atsushi Suzuki、Kohei Suzuki

Coatings 5 ( 4 ) 646 - 655 2015.10

Fabrication and characterization of organic solar cells using metal complex of phthalocyanines Reviewed International journal

Tomoyasu Kida, Atsushi Suzuki, Tsuyoshi Akiyama, and Takeo Oku

AIP Conference Proceedings 1649 102 - 106 2015.4

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT Reviewed International journal

Atsushi Suzuki, Ryo Furukawa, Tsuyoshi Akiyama and Takeo Oku

AIP Conference Proceedings 1649 107 - 112 2015.4

Effects of Niobium Addition into TiO2 Layers on CH3NH3PbI3-based Photovoltaic Devices Reviewed International journal

Takeo Oku, Taishi Iwata, Atsushi Suzuki

Chemistry Letters 44 1033 - 1035 2015.4

Language：English Publishing type：Research paper (scientific journal) Participation form：Joint(The vice charge)

TiO2/CH3NH3PbI3-based photovoltaic devices were fabricated by a spin-coating method using a mixture solution of niobium(V) ethoxide, and the effects of niobium (Nb) addition to TiO2 layers were investigated. The lattice distance and energy gap of the TiO2 were almost same after Nb addition. The elemental mapping and sheet resistance measurements indicated a wide distribution of Nb and Ti, and a decrease in sheet resistance by Nb addition. The external quantum efficiency and internal quantum efficiency increased by Nb addition to compact TiO2 and mesoporous TiO2 layers, which resulted in an increase in the current density and conversion efficiency of the cell.

Effects of Niobium Addition into TiO2 Layers on CH3NH3PbI3-based Photovoltaic Devices Reviewed

Takeo Oku, Taishi Iwata, Atsushi Suzuki

Chemistry Letters 44 1033 - 1035 2015.4

Language：English Publishing type：Research paper (scientific journal)

Formation of Thin Films of Densely Packed [60]Fullerene-Diaminoethane Adduct Microparticles at a Liquid/Liquid Interface and Their Photoelectrochemical Applications Reviewed

Shoto Banya, Tsuyoshi Akiyama, Daisuke Izumoto, Atsushi Suzuki, Takeo Oku

CHEMISTRY LETTERS 44 ( 4 ) 489 - 491 2015.4

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Thin films of [60]fullerene-1,2-diaminoethane adduct microparticles (C60P) were fabricated via a liquid/liquid interface precipitation. The energy level of the lowest unoccupied molecular orbital (LUMO) of the CO was evaluated by electrochemical analysis. The additional tetraphenylporphyrin substantially enhanced the photocurrent from the C60P-thin-film-modified electrode.

DOI： 10.1246/cl.141153

Web of Science

Fabrication and characterization of siliconnaphthalocyanine/fullerene-basedphotovoltaic devices with inverted structures Reviewed International journal

H. Maruhashi, T. Oku, A. Suzuki, and T. Akiyama

Proc. Int. Conf. and Summer School on Advanced Silicide Technology 2014, JJAP Conf. Proc. 011405-1 - 011405-7 2015.3

Effects of Triphenylborane Addition to Decaphenylcyclopentasilane Thin Films Reviewed International journal

Takeo Oku, Naoki Hibi, Atsushi Suzuki, Tsuyoshi Akiyama,Masahiro Yamada, Sakiko Fukunishi and Kazufumi Kohno

Proc. Int. Conf. and Summer School on Advanced Silicide Technology 2014, JJAP Conf. Proc. 011404-1 - 011404-6 2015.3

Fabrication and characterization of siliconnaphthalocyanine/fullerene-basedphotovoltaic devices with inverted structures Reviewed

H. Maruhashi, T. Oku, A. Suzuki, T. Akiyama

Proc. Int. Conf. and Summer School on Advanced Silicide Technology 2014, JJAP Conf. Proc. 011405-1 - 011405-7 2015.3

Effects of Triphenylborane Addition to Decaphenylcyclopentasilane Thin Films Reviewed

Takeo Oku, Naoki Hibi, Atsushi Suzuki, Tsuyoshi Akiyama, Masahiro Yamada, Sakiko Fukunishi, Kazufumi Kohno

Proc. Int. Conf. and Summer School on Advanced Silicide Technology 2014, JJAP Conf. Proc. 011404-1 - 011404-6 2015.3

Electronic Structures and Magnetic Properties of Shuttle Cock-Type of Phthalocyanine Reviewed International journal

Atsushi Suzuki and Takeo Oku

4th Annual International Conference Proceeding, Sustainable Energy and Environmental Sciences (SEES 2015) 89 - 93 2015.2

Electronic Structures and Magnetic Properties of Shuttle Cock-Type of Phthalocyanine Reviewed

Atsushi Suzuki, Takeo Oku

4th Annual International Conference Proceeding, Sustainable Energy and Environmental Sciences (SEES 2015) 89 - 93 2015.2

Fabrication and Characterization of Perovskite based Solar Cells using Lead Phthalocyanine as Hole Transport Layer Reviewed

Atsushi Suzuki, Tomoyasu Kida and Takeo Oku

4th Annual International Conference Proceeding, Sustainable Energy and Environmental Sciences (SEES 2015) 85 - 88 2015.2

Fabrication and Characterization of Perovskite based Solar Cells using Lead Phthalocyanine as Hole Transport Layer Reviewed

Atsushi Suzuki, Tomoyasu Kida, Takeo Oku

4th Annual International Conference Proceeding, Sustainable Energy and Environmental Sciences (SEES 2015) 85 - 88 2015.2

Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine Reviewed International journal

Haruto Maruhashi, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, and Yasuhiro Yamasaki

AIP Conference Proceedings 1649 89 - 95 2015.1

Microstructures and properties of CH3 NH3 PbI3− x Clx hybrid solar cells Reviewed International journal

Kohei Suzuki, Atsushi Suzuki, Masahito Zushi and Takeo Oku

AIP Conference Proceedings 1649 96 - 101 2015.1

Fabrication and characterization of photovoltaic devices based on perovskite compounds with TiO2 nanoparticles Reviewed International journal

Masato Kanayama, Takeo Oku, Atsushi Suzuki, Masahiro Yamada, Sakiko Fukunishi, Kazufumi Kohno, and Hiroki Sakamoto

AIP Conference Proceedings 164 84 - 88 2015.1

Formation of Thin Films of Densely Packed [60]FullereneDiaminoethane Adduct Microparticles at a Liquid/Liquid Interface and Their Photoelectrochemical Applications Reviewed

Shoto Banya, Tsuyoshi Akiyama, Daisuke Izumoto, Atsushi Suzuki, and Takeo Oku

Chem. Lett. 44 ( 4 ) 489 - 491 2015.1

Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine Reviewed

Haruto Maruhashi, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

IRAGO CONFERENCE 2014 1649 89 - 95 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

[6,6]-phenyl C-61-butyric acid methyl ester and poly(3-hexylthiophene) bulk heterojunction solar cells added with zinc-tetra-tertiary-butyl-phthalocyanine (ZnPc) were fabricated and characterized. The photovoltaic properties of the solar cells with an inverted structure were improved by the ZnPc addition, which were investigated on the bases of current density-voltage characteristics, incident photon to current conversion efficiency.

DOI： 10.1063/1.4913550

Web of Science

Microstructures and properties of CH3NH3PbI3-xClx hybrid solar cells Reviewed

Kohei Suzuki, Atsushi Suzuki, Masahito Zushi, Takeo Oku

IRAGO CONFERENCE 2014 1649 96 - 101 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Halide-perovskite CH3NH3PbI3 was produced on mesoporous TiO2 layer by spin-coating a precursor solution of PbCl2 and CH3NH3I in dimethylformamide. The role of the annealing process and chlorine (Cl) doping for the perovskite-phase formation was investigated. It was found that crystallization of the perovskite materials was stimulated by the annealing process, and that longer annealing time is necessary for the Cl-doped perovskite compared with that of non-doped perovskite phase.

DOI： 10.1063/1.4913551

Web of Science

Microstructures and properties of CH3NH3PbI3-xClx hybrid solar cells Reviewed

Kohei Suzuki, Atsushi Suzuki, Masahito Zushi, Takeo Oku

IRAGO CONFERENCE 2014 1649 96 - 101 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

DOI： 10.1063/1.4913551

Web of Science

Fabrication and characterization of photovoltaic devices based on perovskite compounds with TiO2 nanoparticles Reviewed

Masato Kanayama, Takeo Oku, Atsushi Suzuki, Masahiro Yamada, Sakiko Fukunishi, Kazufumi Kohno, Hiroki Sakamoto

IRAGO CONFERENCE 2014 1649 84 - 88 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Perovskite-type photovoltaic devices were fabricated by a spin-coating method using a mixture solution. The compact and meso-porous TiO2 of the solar cells were fabricated from TiO2 nanoparticles and sol, and the photovoltaic properties and microstructures were characterized. The conversion efficiencies were improved by the combination of TiO2 nanoparticles and sol. Current density was also improved by increasing numbers of spin-coatings of meso-porous TiO2. Thick meso-porous TiO2 layers would assist the construction of perovskite layers and block of the leak current.

DOI： 10.1063/1.4913549

Web of Science

Fabrication and characterization of photovoltaic devices based on perovskite compounds with TiO2 nanoparticles Reviewed

Masato Kanayama, Takeo Oku, Atsushi Suzuki, Masahiro Yamada, Sakiko Fukunishi, Kazufumi Kohno, Hiroki Sakamoto

IRAGO CONFERENCE 2014 1649 84 - 88 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

DOI： 10.1063/1.4913549

Web of Science

Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine Reviewed

Haruto Maruhashi, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

IRAGO CONFERENCE 2014 1649 89 - 95 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

DOI： 10.1063/1.4913550

Web of Science

Fabrication and Characterization of Inverted Organic Solar Cells using Shuttle Cock-Type Metal Phthalocyanine and PCBM:P3HT Reviewed

Atsushi Suzuki, Ryo Furukawa, Tsuyoshi Akiyama, Takeo Oku

IRAGO CONFERENCE 2014 1649 107 - 112 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance.

DOI： 10.1063/1.4913553

Web of Science

Fabrication and Characterization of Organic Solar Cells using Metal Complex of Phthalocyanines Reviewed

Tomoyasu Kida, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

IRAGO CONFERENCE 2014 1649 102 - 106 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Fabrication and characterization of organic solar cells using shuttle-cock-type phthalocyanines were carried out. Photovoltaic properties of the solar cells with inverted structures were investigated by current density-voltage characteristics. Effects of phase transition between H and J aggregates on the photovoltaic and optical properties were investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed.

DOI： 10.1063/1.4913552

Web of Science

Fabrication and characterization of organic solar cells using titanylphthalocyanine as hole transport layer Reviewed

Makoto Iwase, Atsushi Suzuki, Tsuyoshi Akiyama, and Takeo Oku

Phys. Status Solidi A 211 ( 12 ) 2861 - 2864 2014.8

C60–ethylenediamine adduct thin film as a buffer layer for inverted-type organic solar cells Reviewed

Yuji Ono, Tsuyoshi Akiyama, Shoto Banya, Daisuke Izumoto, Jo Saito, Katsuhiko Fujita, Hiroshi Sakaguchi, Atsushi Suzuki and Takeo Oku

The Royal Society of Chemistry Advances 4 34950 - 34954 2014.8

Role of scandium atom in ScxY3−xN@C80(CF3)n (n = 0, 2) on nuclear quadrupole interaction, electric field gradient and asymmetric parameters Reviewed

Atsushi Suzuki, Takeo Oku

Microelectronic Engineering 126 ( 25 ) 113 - 117 2014.7

Role of scandium atom in ScxY3−xN@C80(CF3)n (n = 0, 2) on nuclear quadrupole interaction, electric field gradient and asymmetric parameters Reviewed

Atsushi Suzuki, Takeo Oku

Microelectronic Engineering 126 ( 25 ) 113 - 117 2014.7

Effect of Au nanoparticle addition to hole transfer layer in organic solar cells based on copper naphthalocyaine and fullerene Reviewed

Akihiko Nagata, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki

Progress in Natural Science Materials International 24 179 - 183 2014.6

Fabrication and Characterization of TiO2/CH3NH3PbI3-based Photovoltaic Devices Reviewed

Masahito Zushi, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

Chemistry Letter 43 ( 6 ) 916 - 918 2014.6

Fabrication and Characterization of TiO2/CH3NH3PbI3-based Photovoltaic Devices Reviewed

Masahito Zushi, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

CHEMISTRY LETTERS 43 ( 6 ) 916 - 918 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

TiO2/CH3NH3PbI3-based photovoltaic devices were fabricated by a spin-coating method using a mixture solution. Photovoltaic properties of the solar cells were investigated by optical absorption, current density-voltage characteristics, and incident photon to current conversion efficiency. Effects of TiO2 addition and hole-transport layers were also investigated. Microstructures of the cells were investigated by transmission electron microscopy, which indicated a nanoparticle structure of TiO2, and atomic arrangements of Pb atoms in the CH3NH3PbI3 crystal were also directly observed.

DOI： 10.1246/cl.140127

Web of Science

Effects of Au nanoparticle addition to hole transfer layer in organic solar cells based on copper naphthalocyanine and fullerene Reviewed

Akihiko Nagata, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki

PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL 24 ( 3 ) 179 - 183 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Organic solar cells based on copper naphthalocyanine (CuNc) and fullerene ((C-60) were fabricated, and their photovoltaic properties were investigated. C-60 and CuNc were used as n-type and p-type semiconductors, respectively. In addition, the effect of Au nanoparticle addition on a hole transfer layer was investigated, and the power conversion efficiency of the devices).vas improved after blending the Au nanoparticles into the hole transport layer. Nanostruchtres of Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructure and electronic properties were discussed. (c) 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.pnsc.2014.04.002

Web of Science

Fabrication and characterization of PCBM:P3HT:silicon phthalocyanine bulk heterojunction solar cells with inverted structures Reviewed

Takeo Oku, Satoru Hori, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

JAPANESE JOURNAL OF APPLIED PHYSICS 53 ( 5 ) 05FJ08-1 - 05FJ08-5 2014.5

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

[6,6]-phenyl C-61-butyric acid methyl ester and poly(3-hexylthiophene) bulk heterojunction solar cells doped with silicon phthalocyanine (SiPc) were fabricated and characterized. The photovoltaic properties of the solar cells with an inverted structure were improved by the SiPc addition, which were investigated on the bases of current density-voltage characteristics, incident photon to current conversion efficiency, and internal quantum efficiency. The solar cell with the inverted structure also showed good stability in air compared with the normal stacking devices. The microstructure of the solar cells was investigated by X-ray diffraction and transmission electron microscopy, and the carrier separation and transfer of the solar cells were discussed. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.05FJ08

Web of Science

Electronic structures and magnetic properties of Sc2YN@C-80(CF3)(2) dimer Reviewed

Atsushi Suzuki, Takeo Oku

JAPANESE JOURNAL OF APPLIED PHYSICS 53 ( 5 ) 05FN02 - 05FN05 2014.5

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

Electronic structures and magnetic properties of a Sc2YN@C-80(CF3)(2) dimer, a Sc3N@C-80(CF3)(2) dimer, and Sc2YN@C-80(CF3)(2) were investigated by quantum calculation using the density functional theory. The effect of the perturbation of dimerization on the electronic structure was based on the distorted molecular structure of the electron density distribution with an s,p, d-hybrid orbital at decreasing energy levels near the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Magnetic parameters of the isotropic chemical shifts of N-14, Sc-45, and C-13-NMR in N-14, Sc-45, and C-13 atoms on the fullerene cage were calculated. The chemical shifts of Sc-45 and N-14 atoms in a dimer were due to the dipole-dipole and nuclear quadrupole interactions generated by an electrostatic potential with a slight modified electron density distribution and an atomic charge around a nucleus. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.05FN01

Web of Science

Electronic structures and magnetic properties of Sc4O2@C-80(CF3)(n) (n=2 and 4) Reviewed

Yuma Abe, Atsushi Suzuki, Takeo Oku

JAPANESE JOURNAL OF APPLIED PHYSICS 53 ( 5 ) 05FN02 - 05FN05 2014.5

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

The electronic structures and magnetic properties of endohedral metallofullerenes based on an encapsulated scandium oxide cluster of Sc4O2 within a C-80 fullerene cage with the trifluoromethyl group CF3 were studied for nuclear magnetic resonance (NMR) quantum computers for the control of nuclear spin gates. The effects of the trifluoromethyl group with the fullerene cage on electronic structures and magnetic properties were investigated by quantum calculation using the density function theory. The addition of the substituent group CF3 on Sc4O2@C-80(CF3)(4) caused asymmetrical electronic structures and magnetic parameters with a widely separated chemical shift of C-13, Sc-45, and O-17-NMR. The isotropic A-tensor in the hyperfine coupling constant of ScII atoms in the Sc4O2@(80)(CF3)(2) cation radical originated from the electron density distribution localized on the s-orbital in Sc atoms. The spin-lattice relaxation time of 45Sc in the Sc4O2@C-80(CF3)(2) cation was calculated to be 72 mu s, which can be applied to the use of nuclear spins as quantum bits in NMR quantum computers. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.05FN02

Web of Science

Effect of gold nanoparticle in hole-transport layer on inverted organic thin-film solar cell performance Reviewed

Tsuyoshi Akiyama, Takuji Nishida, Taisuke Matsumoto, Hiroshi Sakaguchi, Atsushi Suzuki, Takeo Oku

Physica Status Solidi A 211 1645 - 1650 2014.4

Fabrication and characterization of PCBM:P3HT:silicon phthalocyanine bulk heterojunction solar cells with inverted structures Reviewed

Takeo Oku, Satoru Hori, Atsushi Suzuki, Tsuyoshi Akiyama and Yasuhiro Yamasaki

Japanese Journal of Applied Physics 53 05FJ08-1 - 05FJ08-5 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Science

[6,6]-phenyl C61-butyric acid methyl ester and poly(3-hexylthiophene) bulk heterojunction solar cells doped with silicon phthalocyanine (SiPc) were fabricated and characterized. The photovoltaic properties of the solar cells with an inverted structure were improved by the SiPc addition, which were investigated on the bases of current density–voltage characteristics, incident photon to current conversion efficiency, and internal quantum efficiency. The solar cell with the inverted structure also showed good stability in air compared with the normal stacking devices. The microstructure of the solar cells was investigated by X-ray diffraction and transmission electron microscopy, and the carrier separation and transfer of the solar cells were discussed.

DOI： doi:10.7567/JJAP.53.05FJ08

Electronic structures and magnetic properties of Sc4O2@C80(CF3)n (n = 2 and 4) Reviewed

Yuma Abe, Atsushi Suzuki and Takeo Oku

Japanese Journal of Applied Physics 53 05FN02 - 05FN05 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Science Participation form：Joint(The main charge)

The electronic structures and magnetic properties of endohedral metallofullerenes based on an encapsulated scandium oxide cluster of Sc4O2 within a C80 fullerene cage with the trifluoromethyl group CF3 were studied for nuclear magnetic resonance (NMR) quantum computers for the control of nuclear spin gates. The effects of the trifluoromethyl group with the fullerene cage on electronic structures and magnetic properties were investigated by quantum calculation using the density function theory. The addition of the substituent group CF3 on Sc4O2@C80(CF3)4 caused asymmetrical electronic structures and magnetic parameters with a widely separated chemical shift of 13C, 45Sc, and 17O-NMR. The isotropic A-tensor in the hyperfine coupling constant of ScII atoms in the Sc4O2@C80(CF3)2 cation radical originated from the electron density distribution localized on the s-orbital in Sc atoms. The spin–lattice relaxation time of 45Sc in the Sc4O2@C80(CF3)2 cation was calculated to be 72 µs, which can be applied to the use of nuclear spins as quantum bits in NMR quantum computers.

DOI： doi:10.7567/JJAP.53.05FN02

Electronic structures and magnetic properties of Sc2YN@C80(CF3)2 dimer Reviewed

Atsushi Suzuki and Takeo Oku

Japanese Journal of Applied Physics 53 05FN02 - 05FN05 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Science Participation form：Joint(The main charge)

Electronic structures and magnetic properties of a Sc2YN@C80(CF3)2 dimer, a Sc3N@C80(CF3)2 dimer, and Sc2YN@C80(CF3)2 were investigated by quantum calculation using the density functional theory. The effect of the perturbation of dimerization on the electronic structure was based on the distorted molecular structure of the electron density distribution with an s,p,d-hybrid orbital at decreasing energy levels near the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Magnetic parameters of the isotropic chemical shifts of 14N, 45Sc, and 13C-NMR in 14N, 45Sc, and 13C atoms on the fullerene cage were calculated. The chemical shifts of 45Sc and 14N atoms in a dimer were due to the dipole–dipole and nuclear quadrupole interactions generated by an electrostatic potential with a slight modified electron density distribution and an atomic charge around a nucleus.

DOI： doi:10.7567/JJAP.53.05FN01

Fabrication and Characterization of Phthalocyanine-Based Organic Solar Cells Reviewed

Makoto Iwase, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

Materials Sciences and Applications 5 278 - 284 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Scientific Research Participation form：Joint(The main charge)

Organic solar cells using poly (copper phthalocyanine), copper tetrakis (4-cumylphenoxy) phthalocyanine, copper phthalocyanine and titanyl phthalocyanine were fabricated and characterized. Photovoltaic properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristic and incident photon to current conversion efficiency. These phthalocyanines absorbed light with wavelength longer than 500 nm. A carrier transport mechanism is proposed based on the energy level diagram.

DOI： DOI: 10.4236/msa.2014.55033

Fabrication and Characterization of Phthalocyanine-Based Organic Solar Cells Reviewed

Makoto Iwase, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

Materials Sciences and Applications 5 278 - 284 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Scientific Research

DOI： 10.4236/msa.2014.55033

Photovoltaic properties and morphology of organic solar cells based on liquid-crystal semiconducting polymer with additive Reviewed

Atsushi Suzuki, Masahito Zushi, Hisato Suzuki, Shinichi Ogahara, Tsuyoshi Akiyama and Takeo Oku

AIP Conf. Proc. 1585 164 - 170 2014.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AIP Proceedings Participation form：Joint(The main charge)

Bulk heterojunction organic solar cell based on liquid crystal semiconducting polymers of poly[9,9-dioctylfluorene-co-bithiophene] (F8T2) as p-type semiconductors and fullerenes (C60) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as electron donor and acceptor has been fabricated and characterized for improving photovoltaic and optical properties. The photovoltaic performance including current voltage curves in the dark and illumination of the F8T2/C60 conventional and inverted bulk heterojunction solar cells were investigated. Relationship between the photovoltaic properties and morphological behavior was focused on tuning for optimization of photo-voltaic performance under annealing condition near glass transition temperature. Additive-effect of diiodooctane (DIO) and poly(3-hexylthiophene-2,5-diyl) (P3HT) on the photovoltaic performance and optical properties was investigated. Mechanism of the photovoltaic properties of the conventional and inverted solar cells will be discussed by the experimental results.

DOI： DOI: 10.1063/1.4866636

Effects of Germanium Tetrabromide Addition to Zinc Tetraphenyl Porphyrin / Fullerene Bulk Heterojunction Solar Cells Reviewed

Atsushi Suzuki, Kenta Nishimura and Takeo Oku

Electronics 3 112 - 121 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG Participation form：Joint(The main charge)

The effects of germanium tetrabromide addition to tetraphenyl porphyrin zinc (Zn-TPP)/fullerene (C60) bulk heterojunction solar cells were characterized. The light-induced charge separation and charge transfer were investigated by current density and optical absorption. Addition of germanium tetrabromide inserted into active layer of Zn-TPP/C60 as bulk heterojunction had a positive effect on the photovoltaic and optical properties. The photovoltaic mechanism of the solar cells was discussed by experimental results. The photovoltaic performance was due to light-induced exciton promoted by insert of GeBr4 and charge transfer from HOMO of Zn-TPP to LUMO of C60 in the active layer.

DOI： doi:10.3390/electronics3010112

Effects of germanium tetrabromide addition to zinc tetraphenyl porphyrin / fullerene bulk heterojunction solar cells Reviewed

Atsushi Suzuki, Kenta Nishimura, Takeo Oku

Electronics (Switzerland) 3 ( 1 ) 112 - 121 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG

DOI： 10.3390/electronics3010112

Scopus

Photovoltaic Properties and Morphology of Organic Solar Cells based on Liquid-crystal Semiconducting Polymer with Additive Reviewed

Atsushi Suzuki, Masahito Zushi, Hisato Suzuki, Shinichi Ogahara, Tsuyoshi Akiyama, Takeo Oku

IRAGO CONFERENCE 2013 1585 164 - 170 2014

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

Bulk heterojunction organic solar cell based on liquid crystal semiconducting polymers of poly[9,9-dioctylfluorene-co-bithiophene] (F8T2) as p-type semiconductors and fullerenes (C-60) and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) as electron donor and acceptor has been fabricated and characterized for improving photovoltaic and optical properties. The photovoltaic performance including current voltage curves in the dark and illumination of the F8T2/C-60 conventional and inverted bulk heterojunction solar cells were investigated. Relationship between the photovoltaic properties and morphological behavior was focused on tuning for optimization of photo-voltaic performance under annealing condition near glass transition temperature. Additive-effect of diiodooctane (DIO) and poly(3-hexylthiophene-2,5-diyl) (P3HT) on the photovoltaic performance and optical properties was investigated. Mechanism of the photovoltaic properties of the conventional and inverted solar cells will be discussed by the experimental results.

DOI： 10.1063/1.4866636

Web of Science

C-60-ethylenediamine adduct thin film as a buffer layer for inverted-type organic solar cells Reviewed

Yuji Ono, Tsuyoshi Akiyama, Shoto Banya, Daisuke Izumoto, Jo Saito, Katsuhiko Fujita, Hiroshi Sakaguchi, Atsushi Suzuki, Takeo Oku

RSC ADVANCES 4 ( 66 ) 34950 - 34954 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Thin films of a C-60-ethylenediamine (EDA) adduct were prepared from an EDA solution of the adduct particles. An inverted-type organic thin-film solar cell using the thin film of the C-60-EDA adduct as a buffer layer was fabricated. The solar cell performance suggested that the C-60-EDA adduct thin film functioned as an electron-transporting layer, similarly to the titanium oxides in typical inverted-type organic thin-film solar cells.

DOI： 10.1039/c4ra03965c

Web of Science

Effect of gold nanoparticle in hole-transport layer on inverted organic thin-film solar cell performance Reviewed

Tsuyoshi Akiyama, Takuji Nishida, Taisuke Matsumoto, Hiroshi Sakaguchi, Atsushi Suzuki, Takeo Oku

Physica Status Solidi (A) Applications and Materials Science 211 ( 7 ) 1645 - 1650 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley-VCH Verlag

Inverted-type bulk-heterojunction organic thin-film solar cells with incorporated gold nanoparticles were fabricated and evaluated. Gold nanoparticles were incorporated into the hole-transport layer, and subsequently positioned behind the photoactive layer, away from the light-facing side of the solar cell. Incorporation of gold nanoparticles was confirmed by scanning electro microscopy, atomic force microscopy, and transmission absorption spectra. The incorporation of the gold nanoparticles improved the performance of the photovoltaic device, even gold nanoparticles were aggregated in the hole-transport layer. © 2014 WILEY-VCH Verlag GmbH &amp
Co. KGaA, Weinheim.

DOI： 10.1002/pssa.201330674

Scopus

Fabrication and characterization of organic solar cells using titanylphthalocyanine as hole transport layer Reviewed

Makoto Iwase, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

Physica Status Solidi (A) Applications and Materials Science 211 ( 12 ) 2861 - 2864 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley-VCH Verlag

Organic solar cells using titanylphthalocyanine as a hole transport layer (HTL) were fabricated and characterized. Photovoltaic properties of the solar cells with inverted structures were investigated by optical absorption and current density-voltage (J-V) characteristic. The titanylphthalocyanine was mainly used as a buffer layer instead of PEDOT:PSS, and worked as HTL protecting the active layers.

DOI： 10.1002/pssa.201431068

Scopus

Fabrication and characterization of PCBM:P3HT bulk heterojunction solar cells doped with silicon naphthalocyanine Reviewed

Takeo Oku, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama and Yasuhiro Yamasaki

Phys. Status Solidi C 10 ( 12 ) 1836 - 1839 2013.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley Participation form：Joint(The vice charge)

[6,6]-phenyl C61-butyric acid methyl ester: poly(3-hexylthiophene) bulk heterojunction solar cells doped with silicon naphthalocyanine were fabricated and characterized. Photovoltaic properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristic, incident photon to current conversion efficiency, and internal quantum efficiency. The silicon naphthalocyanine blended as the third component absorbed near-infrared light. Microstructure of the solar cells was investigated by X-ray diffraction, and energy levels of the solar cells were discussed.

DOI： DOI: 10.1002/pssc.201300369

Influence of chemical substitution in ScxY3-xN@C80(CF3)n endohedral fullerenes on magnetic properties Reviewed

Atsushi Suzuki, Takeo Oku

Physica B 428 18 - 26 2013.11

Fabrication and Characterization of PCBM:P3HT Bulk Heterojunction Solar Cells Doped with Germanium Phthalocyanine or Germanium Naphthalocyanine Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Materials Sciences and Applications 4 1 - 5 2013.5

Fabrication and Characterization of PCBM:P3HT Bulk Heterojunction Solar Cells Doped with Germanium Phthalocyanine or Germanium Naphthalocyanine Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Materials Sciences and Applications 4 1 - 5 2013.5

Fabrication and characterization of polysilane: PCBM bulk heterojunction solar cells Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Mika Nakamura, Masahiro Yamada

Central European Journal of Engineering 3 ( 2 ) 165 - 169 2013.4

Microstructures and Photovoltaic Properties of Polysilane-Based Solar Cells Reviewed

Takeo Oku, Junya Nakagawa, Makoto Iwase, Atsushi Kawashima, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada, Mika Nakamura,

Japanese Journal of Applied Physics 52 04CR07-1 - 04CR07-5 2013.4

Effects of phosphorous doping to poly (methylphenyl silane) and fabrication of thin film solar cells Reviewed

Junya Nakagawa, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada and Mika Nakamura

Journal of Physics: Conference Series 433 12026 - 12033 2013.4

Fabrication and characterization of silicon naphthalocyanine, gallium phthalocyanine and fullerene-based organic solar cells with inverted structures Reviewed

Takeo Oku, Shigefumi Nose, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama and Yasuhiro Yamasaki

Journal of Physics: Conference Series 433 12025 - 12032 2013.4

Fabrication and characterization of copper oxide-zinc oxide solar cells prepared by electrodeposition Reviewed

Kazuya Fujimoto, Takeo Oku, Tsuyoshi Akiyama and Atsushi Suzuki

Journal of Physics: Conference Series 433 12024 - 12031 2013.4

Electronic structure and magnetic properties of endohedral metallofullerenes based on mixed metal cluster within fullerene cage with trifluoromethyl groups Reviewed

Atsushi Suzuki and Takeo Oku

Journal of Physics: Conference Series 433 12004 - 12011 2013.4

Fabrication and characterization of polymer tandem solar cells Reviewed

Haruto Maruhashi, Atsushi Suzuki, Tsuyoshi Akiyama and Takeo Oku

Journal of Physics: Conference Series 433 12023 - 12029 2013.4

Magnetic properties of endohedral metallofullerenes based on asymmetric nitride yttrium cluster within azafullerenes Reviewed

Hitoshi Nakagawa, Atsushi Suzuki and Takeo Oku

Journal of Physics: Conference Series 433 012005-1 - 012005-7 2013.4

Microstructures and photovoltaic properties of polysilane-based solar cells Reviewed

Takeo Oku, Junya Nakagawa, Makoto Iwase, Atsushi Kawashima, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada, Mika Nakamura

Japanese Journal of Applied Physics 52 ( 4 ) 04CR07-1 - 04CR07-5 2013.4

Language：English Publishing type：Research paper (international conference proceedings) Publisher：The Japan Society of Applied Physics

Polysilane-based organic solar cells with bulk heterojunction and heterojunction structures were fabricated by spin-coating using a mixture solution. Microstructures of the solar cells were investigated by X-ray diffraction analysis and transmission electron microscopy, which indicated a nanocomposite and amorphous structure. The effects of phosphorus and boron doping into polysilanes were investigated by electrical measurements, Raman scattering analysis and Hall effect measurements. Here, we discuss the photovoltaic properties and microstructures of the solar cells. Energy levels in the present solar cells are also discussed. © 2013 The Japan Society of Applied Physics.

DOI： 10.7567/JJAP.52.04CR07

Scopus

Microstructures and photovoltaic properties of C60 based solar cells with copper oxides, CuInS2, phthalocyanines, porphyrin, PVK, nanodiamond, germanium and exciton diffusion blocking layers Reviewed

T. Oku, A. Takeda, A. Nagata, H. Kidowaki, K. Kumada, K. Fujimoto, A. Suzuki, T. Akiyama, Y. Yamasaki and E. Osawa

Materials Technology 28 21 - 39 2013.3

Microstructures and photovoltaic properties of C-60 based solar cells with copper oxides, CuInS2, phthalocyanines, porphyrin, PVK, nanodiamond, germanium and exciton diffusion blocking layers Reviewed

T. Oku, A. Takeda, A. Nagata, H. Kidowaki, K. Kumada, K. Fujimoto, A. Suzuki, T. Akiyama, Y. Yamasaki, E. Osawa

MATERIALS TECHNOLOGY 28 ( 1-2 ) 21 - 39 2013.3

Language：English Publishing type：Research paper (scientific journal) Publisher：MANEY PUBLISHING

Organic solar cells have a potential for use in lightweight, flexible, inexpensive and large scale solar cells. However, significant improvements of photovoltaic efficiencies are mandatory for use in future solar power plants. One of the improvements is donor-acceptor proximity in the devices, which are called bulk heterojunction solar cells. Bulk heterojunction is an efficient method to generate free charge carriers, and the charge transfer is possible at the semiconductor interface. The purpose of the present work is to fabricate and characterise C-60 based solar cells with copper oxides, CuInS2, phthalocyanines, porphyrin, poly-vinylcarbazole, nanodiamond, germanium and exciton diffusion blocking layers. In the present work, C-60 and fullerenol [C-60(OH)(10-12)] were used for n-type semiconductors, and metal copper oxides, metal phthalocyanine derivative, porphyrin and poly-vinylcarbazole were used for p-type semiconductors. In addition, nanodiamond and germanium based molecules were added into the active layers of the solar cells. The novel aspect of the research is to investigate the relation between properties and microstructures of the solar cells using transmission electron microscopy, X-ray diffraction and electronic structure calculation. The impact of the research concerns the study of organic solar cells by means of microstructural analysis, property measurements and theoretical calculations.

DOI： 10.1179/1753555712Y.0000000042

Web of Science

Fabrication and characterization of PCBM:P3HT bulk heterojunction solar cells doped with silicon naphthalocyanine Reviewed

Takeo Oku, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 10, NO 12 10 ( 12 ) 1836 - 1839 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：WILEY-V C H VERLAG GMBH

[6,6]-phenyl C-61-butyric acid methyl ester: poly(3-hexylthiophene) bulk heterojunction solar cells doped with silicon naphthalocyanine were fabricated and characterized. Photovoltaic properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristic, incident photon to current conversion efficiency, and internal quantum efficiency. The silicon naphthalocyanine blended as the third component absorbed near-infrared light. Microstructure of the solar cells was investigated by X-ray diffraction, and energy levels of the solar cells were discussed. (c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

DOI： 10.1002/pssc.201300369

Web of Science

Magnetic properties of endohedral metallofullerenes based on asymmetric nitride yttrium cluster within azafullerenes Reviewed

Hitoshi Nakagawa, Atsushi Suzuki, Takeo Oku

IRAGO CONFERENCE 2012 433 012005-1 - 012005-7 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Magnetic properties of endohedral metallofullerene based on asymmetric triyttrium cluster of Y3N within azafullerene cage of C79N were studied to control spin-flop of nuclear magnetic resonance quantum computer. Difference of nuclear magnetic resonance peaks were exerted by symmetry of structure, electron density distribution and magnetic interaction. In the present calculation, magnetic properties of Y3N@C-80, (Y3N@C-80)(-1), Y3N@C-80 (CF3)(2), Y3N@C79N and (C79N)(+1) were compared for spin controlling in nuclear magnetic resonance quantum computers. The chemical shift of Y3N@C79N appeared the highest magnetic field side. Difference of electron density and magnetic parameters are cause of this result. The chemical shift of Y3N@C-80 (CF3)(2) had the widest peak in all of samples. Substituent groups of (CF3)(2) caused the wide peaks by breaking symmetry of the an fullerene cages. The effect of difference of fullerene cage was shown in NMR chemical shift.

DOI： 10.1088/1742-6596/433/1/012005

Web of Science

Influence of chemical substitution in ScxY3-xN@C 80(CF3)n endohedral fullerenes on magnetic properties Reviewed

Atsushi Suzuki, Takeo Oku

Physica B: Condensed Matter 428 18 - 26 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

Electronic structures and magnetic properties on nitride mixed metal cluster within fullerene cage of ScxY3-xN@C 80(CF3)n at n=0, 2 and 8 were studied for controlling spin gate in the nuclear magnetic resonance quantum computer. Addition of trifluoromethyl groups on the fullerene carbon cage encapsulated with nitride mixed metal cluster provided influence of optical properties at excited state and magnetic parameters of chemical shift in 45Sc, 89Y, 14N, 19F and 13C-NMR. The chemical shift was originated in magnetic interaction of nuclear quadruple interaction based on asymmetry of electron field graduation and asymmetrical parameters with a bias value of electrostatic potential and electron density distribution of spd-hybrid orbital by inductive effect. © 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2013.07.013

Scopus

Fabrication and characterization of silicon naphthalocyanine, gallium phthalocyanine and fullerene-based organic solar cells with inverted structures Reviewed

Takeo Oku, Shigefumi Nose, Kazumi Yoshida, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

IRAGO CONFERENCE 2012 433 12025 - 12032 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Fullerene/phthalocyanine solar cells with inverted structures were fabricated, and the photovoltaic properties, optical absorption and microstructrues were investigated. Silicon naphthalocyanine, gallium phthalocyanine, and poly(3-hexylthiophene) were used for donor materials, and 6,6-phenyl C-61-butyric acid methyl ester was also used as an acceptor material. The solar cells with the inverted structure provided higher conversion efficiencies by addition of silicon naphthalocyanine, and had more stability compared to that with normal structure in the air. Nanostructures of the solar cells were investigated by transmission electron microscopy, which indicated the dispersion of nanocrystals in the active layers. Energy levels of the molecules were calculated, and a carrier transport mechanism was proposed.

DOI： 10.1088/1742-6596/433/1/012025

Web of Science

Fabrication and characterization of polysilane: PCBM bulk heterojunction solar cells Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Mika Nakamura, Masahiro Yamada

Central European Journal of Engineering 3 ( 2 ) 165 - 169 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag Wien

Polysilane/fullerene bulk heterojunction solar cells were fabricated on indium tin oxide electrodes by a spin-coating method, and performance and microstructures of the solar cells were investigated. Decaphenylcyclopentasilane (PDPS), polymethlyphenylsilane (PMPS) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were used for the solar cells. The conversion efficiencies of PDPS:PCBM solar cells were higher than those of PMPS:PCBM devises. Transmission electron microscopy and X-ray diffraction indicated that PDPS:PCBM layer had a nanocomposite structure.

DOI： 10.2478/s13531-012-0057-6

Scopus

Fabrication and characterization of polymer tandem solar cells Reviewed

Haruto Maruhashi, Atsushi Suzuki, Tsuyoshi Akiyama, Takeo Oku

Journal of Physics: Conference Series 433 ( 1 ) 12023 - 12029 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Physics Publishing

Polymer tandem solar cells were fabricated and characterized. Copolymer poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly((4,4-octyldithieno(3,2-b:20,30- d)silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl) (PSBTBT) were used as p-type semiconductors, and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was used as an n-type semiconductor. The open circuit voltage was improved up to 0.69 V by using the tandem structure of P3HT:PCBM and PSBTBT:PCBM layers as compared with those of P3HT:PCBM and PSBTBT:PCBM single cell of 0.53 V and 0.10 V, respectively. Absorption of the tandem cell was in the range of 400 to 800 nm, which corresponded to a sum of those in P3HT:PCBM and PSBTBT:PCBM single cells.

DOI： 10.1088/1742-6596/433/1/012023

Scopus

Effects of phosphorous doping to poly (methylphenyl silane) and fabrication of thin film solar cells Reviewed

Junya Nakagawa, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada, Mika Nakamura

Journal of Physics: Conference Series 433 ( 1 ) 12026 - 12033 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Physics Publishing

Effects of phosphorus bromine (PBr3) doping to polysilane were investigated for spin-coating thin films. Phosphorus doped poly (methylphenyl silane) (PMPS) provided n-type semiconductor behavior, which was confirmed by Hall effect measurements. Desorption of phenyl and methyl groups in doped PMPS thin films was observed after annealing at 300 °C from Raman scattering measurements and theoretical calculations. The band gap energy of PMPS was measured to be 3.2 eV. Decrease of photoluminescence intensity of PMPS was observed by phosphorus doping. Microstructures of the doped PMPS thin films were investigated by using X-ray diffraction, which indicated doped PMPS had an amorphous structure after annealing. A solar cell with PMPS(PBr 3):poly[3-hexylthiophene] bulk-heterojunction structure was fabricated, and provided a photovoltaic behavior. Formation mechanism and carrier transport mechanism of the doped PMPS thin films were proposed.

DOI： 10.1088/1742-6596/433/1/012026

Scopus

Fabrication and characterization of copper oxide-zinc oxide solar cells prepared by electrodeposition Reviewed

Kazuya Fujimoto, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki

IRAGO CONFERENCE 2012 433 12024 - 12031 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Copper oxide-based heterojunction solar cells were fabricated by electrodeposition, and the electronic and optical properties were investigated. ZnO was used as an n-type semiconductor, and copper oxides were used as p-type semiconductors. A photovoltaic device based on an FTO/ZnO/Cu2O heterojunction structure provided short-circuit current density of 2.7 mAcm(-2) and open circuit voltage of 0.28 V under an air mass 1.5 illumination. Microstructures of the solar cells were investigated by scanning electron microscope and X-ray diffraction, which indicated formation of copper oxides and ZnO. Energy levels of the solar cells were discussed.

DOI： 10.1088/1742-6596/433/1/012024

Web of Science

Electronic structure and magnetic properties of endohedral metallofullerenes based on mixed metal cluster within fullerene cage with trifluoromethyl groups Reviewed

A. Suzuki, T. Oku

Journal of Physics: Conference Series 433 ( 1 ) 12004 - 12011 2013

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Physics Publishing

Endohedral metallofullerenes based on encapsulated nitride scandium cluster within C80 fullerene cage with trifluoromethyl group of CF 3 were characterized as a candidate model for controlling nuclear spin gate in NMR quantum computers. Effects of yttrium in nitride scandium cluster of Sc3N within the fullerene cage with trifluoromethyl group on electronic structures and magnetic properties were investigated. Electronic structure and chemical shifts in 45Sc, 89Y, 19F, 13C and 14N atoms were calculated by quantum calculation using density functional theory. Addition of yttrium in nitride scandium cluster of Sc3N within the fullerene cage provided a different position of chemical shift in 45Sc, 89Y, 19F, 13C and 14N atoms. This result was originated in magnetic interaction with spin-local interaction, dipole-dipole interaction and nuclear quadrupole interaction based on nuclear quadrupole moment and asymmetry of electron field gradient with a bias value of charge and spin density distribution of spd-hybrid orbital by inductive effect.

DOI： 10.1088/1742-6596/433/1/012004

Scopus

Fabrication and Characterization of Bulk Heterojunction Solar Cells Based on Liquid-Crystal Semiconductive Polymer Reviewed

Atsushi Suzuki, Shinichi Ogahara, Tsuyoshi Akiyama, Takeo Oku

Energy and Power Engineering 4 459 - 464 2012.11

Fabrication and Characterization of Bulk Heterojunction Solar Cells Based on Liquid-Crystal Semiconductive Polymer Reviewed

Atsushi Suzuki, Shinichi Ogahara, Tsuyoshi Akiyama, Takeo Oku

Energy and Power Engineering 4 459 - 464 2012.11

Fabrication and Characterization of Phthalocyanine/C60 Solar Cells with Inverted Structure Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Advances in Chemical Engineering and Science 2 461 - 464 2012.10

Fabrication and Characterization of Phthalocyanine/C60 Solar Cells with Inverted Structure Reviewed

Kazumi Yoshida, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Yasuhiro Yamasaki

Advances in Chemical Engineering and Science 2 461 - 464 2012.10

Fabrication and Characterization of Poly[Decaphenylcyclopentasilane]-Based Solar Cells Reviewed

Makoto Iwase, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada, Mika Nakamura

Advances in Materials Physics and Chemistry 2 121 - 125 2012.9

Fabrication and Characterization of Poly[Decaphenylcyclopentasilane]-Based Solar Cells Reviewed

Makoto Iwase, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama, Katsuhisa Tokumitsu, Masahiro Yamada, Mika Nakamura

Advances in Materials Physics and Chemistry 2 121 - 125 2012.9

Microstructures and Photovoltaic Properties of Polysilane/C60-Based Solar Cells Reviewed

Atsushi Kawashima, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi,

Materials Sciences and Applications 3 557 - 561 2012.8

Microstructures and Photovoltaic Properties of Polysilane/C60-Based Solar Cells Reviewed

Atsushi Kawashima, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Materials Sciences and Applications 3 557 - 561 2012.8

Fabrication and characterization of tetracyanoquinodimethane/phthalocyanine solar cells Reviewed

Atsushi Suzuki, Takahiro Ohtsuki, Takeo Oku, Tsuyoshi Akiyama

Materials Science and Engineering B 177 877 - 881 2012.6

Fabrication and characterization of tetracyanoquinodimethane/phthalocyanine solar cells Reviewed

Atsushi Suzuki, Takahiro Ohtsuki, Takeo Oku, Tsuyoshi Akiyama

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS 177 ( 11 ) 877 - 881 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Fabrication and characterization of heterojunction solar cells of tetracyanoquinodimethane (TCNQ)/copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) were carried out. The light-induced charge separation with charge transfer was investigated by light-induced current density and optical absorption. In both cases of the TCNQ/CuPc and TCNQ/ZnPc solar cells, the TCNQ thin film worked for strong electron-accepting layer as n-type semiconductor. These behaviors would be originated in charge transfer of excited electron from CuPc and ZnPc to TCNQ. The photovoltaic mechanism was discussed on the basis of the experimental results. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.mseb.2012.03.052

Web of Science

Effects of germanium addition to copper phthalocyanine / fullerene-based solar cells Reviewed

T. Oku, K. Kumada, A. Suzuki, K. Kikuchi

Cent. Eur. J. Eng. 2 248 - 252 2012.5

Organic Solar Cells Based on Electrodeposited Polyaniline Films Reviewed

Kei Inoue, Tsuyoshi Akiyama, Atsushi Suzuki, Takeo Oku

Japanese Journal of Applied Physics 51 04DK10-1 - 04DK10-4 2012.5

Organic Solar Cells Based on Electrodeposited Polyaniline Films Reviewed

Kei Inoue, Tsuyoshi Akiyama, Atsushi Suzuki, Takeo Oku

JAPANESE JOURNAL OF APPLIED PHYSICS 51 ( 4 ) 04DK10-1 - 04DK10-4 2012.4

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC APPLIED PHYSICS

Polyaniline thin films as hole transporting layers were fabricated on transparent indium-tin-oxide electrodes by electrodeposition of aniline in an aqueous H2SO4 electrolyte solution. Emerald-green polyaniline films were obtained, which showed stable redox waves. A mixed solution of polythiophene and fullerene derivative was spin-coated onto the electrodeposited polyaniline film. After the modification of titanium oxide film on the surface of the polythiophene/fullerene layer, an aluminum electrode was fabricated by vacuum deposition. The obtained solar cells generated stable photocurrent and photovoltage under light illumination. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.04DK10

Web of Science

Effect of an amorphous TiO2 addition on dye-sensitized solar cells with organic dyes Reviewed

Nariaki Kakuta, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Journal of Ceramic Processing Research 13 28 - 31 2012.3

Effect of an amorphous TiO2 addition on dye-sensitized solar cells with organic dyes Reviewed

Nariaki Kakuta, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Journal of Ceramic Processing Research 13 28 - 31 2012.3

Electronic structure and magnetic properties of 31P@C60-SWCNT as peapods Reviewed

Atsushi Suzuki, Takeo Oku

Journal of Physics: Conference Series 352 12012 - 12020 2012.3

Fabrication and characterization of poly[diphenylsilane]-based solar cells Reviewed

M. Iwase, T. Oku, A. Suzuki, T. Akiyama, K. Tokumitsu, M. Yamada, M. Nakamura

Journal of Physics: Conference Series 352 12018 - 152023 2012.3

Microstructures and photovoltaic properties of fullerene-based organic-inorganic hybrid solar cells Reviewed

T. Oku, A. Takeda, A. Nagata, K. Fujimoto, T. Akiyama, A. Suzuki

Journal of Physics: Conference Series 352 12024 - 12033 2012.3

Fabrication and characterization of polysilane/C60 thin film solar cells Reviewed

Junya Nakagawa, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama

Journal of Physics: Conference Series 352 12019 - 12024 2012.3

Fabrication and characterization of polysilane/C60 thin film solar cells Reviewed

Junya Nakagawa, Takeo Oku, Atsushi Suzuki, Tsuyoshi Akiyama

Journal of Physics: Conference Series 352 12019 - 12024 2012.3

Effect of perylenetetracarboxylic dianhydride layer as a hole blocking layer on photovoltaic performance of polyvinylcarbazole: C60 bulk heterojunction thin films Reviewed

Takeo Oku, Katsunori Nomura, Atsushi Suzuki, Kenji Kikuchi

Thin Solid Films 520 2545 - 2548 2012.2

Effect of perylenetetracarboxylic dianhydride layer as a hole blocking layer on photovoltaic performance of poly-vinylcarbazole: C 60 bulk heterojunction thin films Reviewed

Takeo Oku, Katsunori Nomura, Atsushi Suzuki, Kenji Kikuchi

Thin Solid Films 520 ( 7 ) 2545 - 2548 2012.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER

Thin film solar cells with a structure of poly(9-vinylcarbazole) and C 60 bulk heterojunction were fabricated and characterized. The effects of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) as a hole blocking layer for the organic solar cells between active layer and metal layer were also investigated, and the optimized cell structures with PTCDA improved the short-circuit current density and fill factor up to twice values, which resulted in an increase of the conversion efficiency. Microstructure analysis was carried out by using X-ray diffraction and transmission electron microscopy, which indicated the bulk nanocomposite structure Energy levels of the molecules were calculated, and the interfacial structure was discussed based on the experimental and calculated results. © 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2011.10.163

Scopus

Fabrication and Characterization of CuO-based Solar Cells Reviewed

Hiroki Kidowaki, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki, Balachandran Jeyadevan, Jhon Cuya

Journal of Materials Science Research 1 138 - 143 2012.1

Fabrication and Characterization of CuO-based Solar Cells Reviewed

Hiroki Kidowaki, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki, Balachandran Jeyadevan, Jhon Cuya

Journal of Materials Science Research 1 138 - 143 2012.1

Fabrication and characterization of poly[diphenylsilane]-based solar cells Reviewed

M. Iwase, T. Oku, A. Suzuki, T. Akiyama, K. Tokumitsu, M. Yamada, M. Nakamura

ASIA-PACIFIC INTERDISCIPLINARY RESEARCH CONFERENCE 2011 (AP-IRC 2011) 352 12018 - 152023 2012

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Poly[diphenylsilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS, phosphorus and boron. An influence of phosphorus and boron doping into PDPS on the performance of the photovoltaic device was investigated. The solar cell using fluorine doped tin oxide glass plates provided short-circuit current density of 0.12 mA/cm(2) and open-circuit voltage of 0.28 V under simulated sunlight. Energy levels, formation mechanism and microstructure of the solar cells were discussed.

DOI： 10.1088/1742-6596/352/1/012018

Web of Science

Microstructures and photovoltaic properties of fullerene-based organic-inorganic hybrid solar cells Reviewed

T. Oku, A. Takeda, A. Nagata, K. Fujimoto, T. Akiyama, A. Suzuki

ASIA-PACIFIC INTERDISCIPLINARY RESEARCH CONFERENCE 2011 (AP-IRC 2011) 352 12024 - 12033 2012

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

C-60-based bulk heterojunction solar cells were fabricated, and the electronic and optical properties were investigated. C-60 were used as n-type semiconductors, and copper oxides, CuInS2 and diamond were used as p-type semiconductors. Electronic structures of the molecules were investigated by molecular orbital calculation, and energy levels of the solar cells were discussed. Nanostructures of the solar cells were investigated by transmission electron microscopy, electron diffraction and X-ray diffraction, which indicated formation of mixed nanocrystals.

DOI： 10.1088/1742-6596/352/1/012024

Web of Science

Effects of germanium addition to copper phthalocyanine/fullerene-based solar cells Reviewed

Takeo Oku, Kazuma Kumada, Atsushi Suzuki, Kenji Kikuchi

Central European Journal of Engineering 2 ( 2 ) 248 - 252 2012

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag Wien

Copper phthalocyanine/fullerene-based solar cells were fabricated, and the electronic and optical properties were investigated. Effects of germanium addition to the solar cells were also investigated, which resulted in increase of power conversion efficiencies of the solar cells. Nanostructures of the solar cells were investigated by transmission electron microscopy and electron diffraction, which indicated formation of Ge compound nanoparticles in the copper phthalocyanine layers. Energy levels of the solar cells were discussed from the present analysis data.

DOI： 10.2478/s13531-011-0069-7

Scopus

Electronic structure and magnetic properties of P-31@C-60-SWCNT as peapods Reviewed

A. Suzuki, T. Oku

ASIA-PACIFIC INTERDISCIPLINARY RESEARCH CONFERENCE 2011 (AP-IRC 2011) 352 12012 - 12020 2012

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Design of the NMR quantum computer 1D spin chains based on P-31@C-60-SWCNT as peapods was studied. Electronic structure and magnetic properties of P-31@C-60 encapsulating fullerenes within SWCNT as peapods was investigated by quantum chemical calculation. Characterization of shifts of C-13, principle g-tensor and A-tensor of hyperfine structure for phosphorus atom with electronic spin S=3/2 and nuclear spin I=1/2 were studied. The excited energy and wavelength at 1512 nm and 728 nm confirmed assignment of the first and second states as van Hove transitions. Molecular design of carbon peopods is important to control quantum spin qubits, splitting by spin-local interaction and dipole-dipole interaction based on p-orbital spin distribution under hybridization of molecular orbital at excited state and grand state.

DOI： 10.1088/1742-6596/352/1/012012

Web of Science

Effects of Au Nanoparticle Addition to Hole Transfer Layer in Organic Photovoltaic Cells Based on Phthalocyanines and Fullerene Reviewed

Akihiko Nagata, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki, Yasuhiro Yamasaki, and TomohiroMori

Journal of Nanotechnology 2011 869596 - 869602 2011.10

Effects of Au Nanoparticle Addition to Hole Transfer Layer in Organic Photovoltaic Cells Based on Phthalocyanines and Fullerene Reviewed

Akihiko Nagata, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki, Yasuhiro Yamasaki, TomohiroMori

Journal of Nanotechnology 2011 869596 - 869602 2011.10

Theoretical Study of Gallium Phthalocyanine Dimer-Fullerene Complex for Photovoltaic Device Reviewed

Akihiro Takeda, Takeo Oku, Atsushi Suzuki, Yasuhiro Yamasaki

Journal of Modern Physics 2 ( 9 ) 966 - 969 2011.9

Theoretical Study of Gallium Phthalocyanine Dimer-Fullerene Complex for Photovoltaic Device Reviewed

Akihiro Takeda, Takeo Oku, Atsushi Suzuki, Yasuhiro Yamasaki

Journal of Modern Physics 2 ( 9 ) 966 - 969 2011.9

Formation and characterization of phthalocyanine dimer/C60 solar cells Reviewed

A. Takeda, A Minowa, T. Oku, A. Suzuki, K. Kikuchi , Y. Yamasaki

Progress Natural Sci. Mater. Int. 21 27 - 30 2011.9

Fabrication and characterization of porphyrin dye-sensitized solar cells Reviewed

Atsushi Suzuki, Kengo Kobayashi, Takeo Oku, Kenji Kikuchi

Materials Chemistry and Physics 129 ( 41276 ) 236 - 241 2011.9

Fabrication and characterization of porphyrin dye-sensitized solar cells Reviewed

Atsushi Suzuki, Kengo Kobayashi, Takeo Oku, Kenji Kikuchi

MATERIALS CHEMISTRY AND PHYSICS 129 ( 1-2 ) 236 - 241 2011.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Solid dye-sensitized solar cells of porphyrin adsorbed on TiO(2) particles with iodine have been fabricated and characterized. Influence of the porphyrin in the dye-sensitized solar cells on photovoltaic properties was investigated by experimental results. Microstructure and X-ray diffractions suggested that TiO(2) molecules were ordered to form the tetragonal crystal. A slight amount of the crystal disorder caused to inhibit carrier diffusion with recombination at interface between TiO(2) and amorphous porphyrin. Photovoltaic mechanism of the solar cells was discussed by the experimental results using quantum calculation. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matchemphys.2011.04.010

Web of Science

Fabrication and characterization of fullerene / dibenzo-tetrathiafulvalene solar cells Reviewed

Atsushi Suzuki, Katsuya Yano, Takeo Oku

Materials Science Forum 688 80 - 84 2011.6

Geometrical effects of (14N@C60)2, 14N@C60 and C59N endohedral fullerenes within single-walled carbon nanotube as peapods on electronic structure and magnetic properties Reviewed

Atsushi Suzuki, Takeo Oku

Physica B 406 3274 - 3278 2011.6

Geometrical effects of (14N@C60)2, 14N@C60 and C59N endohedral fullerenes within single-walled carbon nanotube as peapods on electronic structure and magnetic properties Reviewed

Atsushi Suzuki, Takeo Oku

Physica B 406 3274 - 3278 2011.6

Fabrication, nanostructures and electronic properties of nanodiamond-based solar cells Reviewed

A. Nagata, T. Oku, K. Kikuchi, A. Suzuki, Y. Yamasaki, E. Ōsawa

Progress in Natural Science: Materials International 20 38 - 43 2011.4

Fabrication, nanostructures and electronic properties of nanodiamond-based solar cells Reviewed

A. Nagata, T. Oku, K. Kikuchi, A. Suzuki, Y. Yamasaki, E. Ōsawa

Progress in Natural Science: Materials International 20 38 - 43 2011.4

Formation and characterization of phthalocyanine dimer/C60 solar cells Reviewed

Akihiro Takeda, Akira Minowa, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Yasuhiro Yamasaki

Progress in Natural Science: Materials International 21 ( 1 ) 27 - 30 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

Organic solar cells with μ-oxo-bridged gallium phthalocyanine dimer (GaPc dimer) and fullerene were produced by an evaporation method. A device based on the GaPc dimer provided a conversion efficiency of 4.2×10-3%, which is better compared to a device based on phthalocyanine monomer. Dimerization effect was discussed with a molecular orbital calculation, and the crystalline phases of the present solar cells were investigated by X-ray diffraction. Further improvement of the efficiency was discussed on the basis of the experimental results.

DOI： 10.1016/S1002-0071(12)60020-3

Scopus

Fabrication and characterization of fullerene/dibenzo-tetrathiafulvalene solar cells Reviewed

Atsushi Suzuki, Katsuya Yano, Takeo Oku

NANO-SCALE AND AMOURPHOUS MATERIALS 688 80 - 84 2011

Language：English Publishing type：Research paper (international conference proceedings) Publisher：TRANS TECH PUBLICATIONS LTD

Fabrication and characterization of fullerene (C-60) / dibenzotetrathiafulvalene (DBTTF) solar cells were carried out. Photovoltaic and optical properties of the organic solar cells were investigated. Transmission electron microscopy, x-ray and electron diffraction confirmed that the bulk heterojunction thin films had microstructure of C-60 crystal phase in DBTTF amorphous phase. The photovoltaic performance of the bulk heterojunction solar cell would be originated in the extent of electron diffusion across interface around the microstructure. Photovoltaic mechanism was discussed on the basis of experimental results.

DOI： 10.4028/www.scientific.net/MSF.688.80

Web of Science

Fabrication and photovoltaic property of diamond: fullerene nanocomposite thin film Reviewed

A. Nagata, T. Oku, A. Suzuki, K. Kikuchi, S. Kikuchi

J. Ceram. Soc. Jpn. 118 1006 - 1008 2010.11

Fabrication and characterization of C60/tetrathiafulvalene solar cells Reviewed

A. Suzuki, K. Inoue, K. Yano, T. Oku and K. Kikuchi

Journal of Physics and Chemistry of Solids 71 1587 - 1591 2010.11

Fabrication and characterization of copper system compound semiconductor solar cells Reviewed

R. Motoyoshi, T. Oku, A. Suzuki, K. Kikuchi, S. Kikuchi, B. Jeyadevan and J. Cuya

Advances in Materials Science and Engineering 2010 562842-1 - 562842-11 2010.11

Structure and photovoltaic activity of cupric oxide-based thin film solar cell Reviewed

R. Motoyosi, T. Oku, H. Kidowaki, A. Suzuki, K. Kikuchi, S. Kikuchi, B. Jeyadeva

J. Ceram. Soc. Jpn. 118 1021 - 1023 2010.11

Fabrication and photovoltaic property of diamond: fullerene nanocomposite thin film Reviewed

A. Nagata, T. Oku, A. Suzuki, K. Kikuchi, S. Kikuchi

J. Ceram. Soc. Jpn. 118 1006 - 1008 2010.11

Structure and photovoltaic activity of cupric oxide-based thin film solar cell Reviewed

R. Motoyosi, T. Oku, H. Kidowaki, A. Suzuki, K. Kikuchi, S. Kikuchi, B. Jeyadeva

J. Ceram. Soc. Jpn. 118 1021 - 1023 2010.11

Fabrication and characterization of copper system compound semiconductor solar cells Reviewed

R. Motoyoshi, T. Oku, A. Suzuki, K. Kikuchi, S. Kikuchi, B. Jeyadevan, J. Cuya

Advances in Materials Science and Engineering 2010 562842-1 - 562842-11 2010.11

Fabrication and characterization of C-60/tetrathiafulvalene solar cells Reviewed

Atsushi Suzuki, Kei Inoue, Katsuya Yano, Takeo Oku, Kenji Kikuchi

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 71 ( 11 ) 1587 - 1591 2010.11

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Fabrication and characterization of C-60/tetrathiafulvalene solar cells was carried out. Photovoltaic properties of bulk-hetero and heterojunciotn solar cells were investigated by light-induced current vs. voltage curves and optical absorption. Transmission electron microscopy (TEM) image, X-ray and electron diffraction showed that the bulk-heterojunction film had the microstructure of C-60 crystal structure with TTF phase. Heat treatment of the heterojunction film with tetraethylsilane improved the photovoltaic performance, yielding a slight increase of conversion efficiency. This result would be originated in improvement of microstructure around inner interface between the both crystal phases. Mechanisms of the photovoltaic properties were discussed on the basis of the experimental results. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jpcs.2010.08.007

Web of Science

Electronic structure and magnetic properties of 14N@C60 within single-walled carbon nanotube as peapods Reviewed

A. Suzuki, T. Oku, K. Kikuchi

Physica B 405 2418 - 2422 2010.5

Electronic structure and magnetic properties of N-14@C-60 within single-walled carbon nanotube as peapods Reviewed

Atsushi Suzuki, Takeo Oku, Kenji Kikuchi

PHYSICA B-CONDENSED MATTER 405 ( 10 ) 2418 - 2422 2010.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Design of spin labels inside for possible molecular spintronics, which contains 1D spin chain filling single-walled carbon nanotube (SWCNT) with magnetic endohedral fullerenes of N-14@C-60, has been suggested. Electronic structure and magnetic properties of N-14@C-60-SWCNT armchair for chiral index (n, n) n=9-13 in contrast with SWCNT and N-14@C-60 were characterized. Especially, influence of the SWCNT diameter on electronic structure, magnetic parameters of chemical shift of C-13, principal gtensor and hyperfine coupling constant of nitrogen atom was investigated by ab-initio density functional theory. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2010.02.057

Web of Science

Fabrication and characterization of fullerene / porphyrin bulk hetero junction solar cells Reviewed

T. Oku, T. Noma, A. Suzuki, K. Kikuchi and S. Kikuchi

J. Phys. Chem. Solids 71 551 - 555 2010.4

Fabrication and Characterization of Fullerene-Based Bulk Heterojunction Solar Cells with Porphyrin, CuInS2, Diamond and Exciton-Diffusion Blocking Layer Reviewed

T. Oku, A. Takeda, A. Nagata, T. Noma, A. Suzuki and K. Kikuchi

Energies 3 671 - 685 2010.4

Magnetic properties of the FeII spin crossover complex in emulsion polymerization of trifluoroethylmethacrylate using poly(vinyl alcohol) Reviewed

A. Suzuki, M. Iguchi, T. Oku, M. Fujiwara

J. Solid State Chem. 183 951 - 956 2010.4

The effects of exciton-diffusion blocking layers on pentacene / C60 bulk hetero junction solar cells Reviewed

K. Nomura, T. Oku, A. Suzuki, K. Kikuchi and G. Kinoshita

J. Phys. Chem. Solids 71 210 - 213 2010.4

Fabrication and characterization of titanium dioxide/copper indium disulfide solar cells Reviewed

R. Motoyoshi, T. Oku, A. Suzuki, K. Kikuchi

J. Ceram. Soc. Jpn. 118 30 - 33 2010.4

The effects of exciton-diffusion blocking layers on pentacene / C60 bulk hetero junction solar cells Reviewed

K. Nomura, T. Oku, A. Suzuki, K. Kikuchi, G. Kinoshita

J. Phys. Chem. Solids 71 210 - 213 2010.4

Magnetic properties of the Fe-II spin crossover complex in emulsion polymerization of trifluoroethylmethacrylate using poly(vinyl alcohol) Reviewed

Atsushi Suzuki, Motoi Iguchi, Takeo Oku, Motoyasu Fujiwara

JOURNAL OF SOLID STATE CHEMISTRY 183 ( 4 ) 951 - 956 2010.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

Influence of chemical substitution in the Fe-II spin crossover complex on magnetic properties in emulsion polymerization of trifluoroethylmethacrylate using poly(vinyl alcohol) as a protective colloid was investigated near its high spin/low spin (HS/LS) phase transition. The obvious bi-stability of the HS/LS phase transition was considered by the identification of multiple spin states between the quintet (S=2) states to single state (S=0) across the excited triplet state (S=1). Magnetic parameters of gradual shifts of anisotropy g-tensor supported by the molecular distortion of the spin crossover complex would arise from a Jahn-Teller effect regarding ligand field theory on the basis of a B3LYP density functional theory using electron spin resonance (ESR) spectrum and X-ray powder diffraction. (C) 2010 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jssc.2010.02.014

Web of Science

Fabrication and Characterization of Fullerene-Based Bulk Heterojunction Solar Cells with Porphyrin, CuInS2, Diamond and Exciton-Diffusion Blocking Layer Reviewed

Takeo Oku, Akihiro Takeda, Akihiko Nagata, Tatsuya Noma, Atsushi Suzuki, Kenji Kikuchi

ENERGIES 3 ( 4 ) 671 - 685 2010.4

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG

Fullerene-based bulk heterojunction solar cells were fabricated, and the electronic and optical properties were investigated. C-60 were used as n-type semiconductors, and porphyrin, CuInS2 and diamond were used as p-type semiconductors. An effect of exciton-diffusion blocking layer of perylene derivative on the solar cells between active layer and metal layer was also investigated. Optimized structures with the exciton-diffusion blocking layer improved conversion efficiencies. Electronic structures of the molecules were investigated by molecular orbital calculation, and energy levels of the solar cells were discussed. Nanostructures of the solar cells were investigated by transmission electron microscopy, electron diffraction and X-ray diffraction, which indicated formation of mixed nanocrystals.

DOI： 10.3390/en3040671

Web of Science

Fabrication and characterization of fullerene/porphyrin bulk heterojunction solar cells Reviewed

Takeo Oku, Tatsuya Noma, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 71 ( 4 ) 551 - 555 2010.4

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Fullerene/porphyrin bulk heterojunction solar cells were fabricated and, the electronic and optical properties were investigated. Effects of exciton-diffusion blocking layer of perylene derivative on the solar cells between active layer and metal layer were also investigated. Optimized structures with the exciton-diffusion blocking layer improved conversion efficiencies. Energy levels of the molecules were calculated and discussed. Nanostructures of the solar cells were investigated by X-ray and electron diffraction, which indicated formation of fullerene/porphyrin mixed crystals. Electronic structures of the molecules were investigated by molecular orbital calculation, and energy levels of the solar cells were discussed. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jpcs.2009.12.034

Web of Science

Fabrication, nanostructures and electronic properties of nanodiamond-based solar cells Reviewed

A.Nagata, T. Oku, K. Kikuchi, A. Suzuki, Y. Yamasaki, E. Osawa

Progress in Natural Science: Materials International 20 38 - 42 2010.2

Fabrication, nanostructures and electronic properties of nanodiamond-based solar cells Reviewed

A.Nagata, T. Oku, K. Kikuchi, A. Suzuki, Y. Yamasaki, E. Osawa

Progress in Natural Science: Materials International 20 38 - 42 2010.2

Fabrication and characterization of titanium dioxide/copper indium disulfide solar cells Reviewed

Ryosuke Motoyoshi, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Journal of the Ceramic Society of Japan 118 ( 1373 ) 30 - 33 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：Ceramic Society of Japan

Copper indium disulfide (CIS)-based solar cells with titanium dioxide (TiO2) were produced on F-doped SnO2 (FTO) by a spin-coating method. The effect of the stacking sequence of the CIS and TiO 2 layers on the electronic properties of the solar cells was investigated. A device based on an FTO/CIS/TiO2 structure provided better cell performance compared to that based on an FTO/TiO2 /CIS structure. The microstructure of TiO2/CIS was examined using energy dispersive X-ray analysis, X-ray diffraction, and transmission electron microscopy, and the TiO2 /CIS solar cells provided bulk heterojunction structures. The energy levels of the present solar cells are also discussed. © 2010 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.118.30

Scopus

Formation and characterization of copper tetrakis (4-cumylphenoxy) phthalocyanine:perylene solar cells Reviewed

R. Motoyoshi, A. Suzuki, K. Kikuchi, T. Oku

Synthetic Metals 159 1345 - 1348 2009.4

Fabrication and characterization of inorganic-organic hybrid solar cells based on CuInS2 Reviewed

A. Takeda, T. Oku, A. Suzuki, K. Kikuchi and S. Kikuchi

J. Ceram. Soc. Jpn. 117 967 - 969 2009.4

Fabrication and characterization of mixture type dye-sensitized solar cells with organic dyes Reviewed

N. Kakuta, T. Oku, A. Suzuki, K. Kikuchi and S. Kikuchi

Journal of the Ceramic Society of Japan 117 964 - 966 2009.4

Role of electrolytes in the preparation of nanoparticles via the emulsion polymerization of vinyl pivalate Reviewed

K. Kikuchi, M. Kitawaki, A. Suzuki, T. Oku

Journal of Colloid and Interface Science 338 480 - 485 2009.4

Formation and characterization of copper tetrakis (4-cumylphenoxy) phthalocyanine:perylene solar cells Reviewed

R. Motoyoshi, A. Suzuki, K. Kikuchi, T. Oku

Synthetic Metals 159 1345 - 1348 2009.4

Role of electrolytes in the preparation of nanoparticles via the emulsion polymerization of vinyl pivalate Reviewed

K. Kikuchi, M. Kitawaki, A. Suzuki, T. Oku

Journal of Colloid and Interface Science 338 480 - 485 2009.4

Fabrication and characterization of inorganic-organic hybrid solar cells based on CuInS2 Reviewed

Akihiro Takeda, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Journal of the Ceramic Society of Japan 117 ( 1369 ) 967 - 969 2009

Language：English Publishing type：Research paper (scientific journal) Publisher：Ceramic Society of Japan

Chalcopyrite compounds/fullerene solar cells based on copper-indium- disulphide and C60 were produced. Two-types of devices with heterojunction and bulk heterojunction structures were examined and characterized. The bulk heterojunction structure provided better efficiency compared to that of the heterojunction structure. Nanostructures of the solar cells were confirmed as mixed nanocrystals by transmission electron microscopy. A photovoltaic mechanism of the present solar cells was discussed on the basis of the experimental results. © 2009 The Ceramic Society of Japan.

DOI： 10.2109/jcersj2.117.967

Scopus

Fabrication and characterization of mixture type dye-sensitized solar cells with organic dyes Reviewed

Nariaki Kakuta, Takeo Oku, Atsushi Suzuki, Kenji Kikuchi, Shiomi Kikuchi

Journal of the Ceramic Society of Japan 117 ( 1369 ) 964 - 966 2009

Language：English Publishing type：Research paper (scientific journal) Publisher：Ceramic Society of Japan

Dye-sensitized solar cells with organic dyes such as xylenol orange, rose bengal and erythrosine B were fabricated and characterized. Gel electrolyte based on polyacrylonitrile was used to improve its durability. A solar cell mixed with xylenol orange and rose bengal showed a wide optical absorption in the visible range, and yielded a high conversion efficiency compared to the other solar cells in the present work. Microstructures of TiO2 electrode was also investigated by transmission electron microscopy and X-ray diffraction. A mechanism of photovoltaic properties of the dye-sensitized solar cells was discussed on experimental results and the energy level diagram. © 2009 The Ceramic Society of Japan.

DOI： 10.2109/jcersj2.117.964

Scopus

High spin/Low spin phase transitions of a spin-crossover complex in the emulsion pooymerization of trifluoroethylmethacrylate (TFEMA) using PVA as a protective colloid. Reviewed

A. Suzuki, M. Fujiwara, N. Masahiko

Colloid and Polymer Science 286 ( 5 ) 525 - 534 2008.4

High spin/Low spin phase transitions of a spin-crossover complex in the emulsion pooymerization of trifluoroethylmethacrylate (TFEMA) using PVA as a protective colloid. Reviewed

A. Suzuki, M. Fujiwara, N. Masahiko

Colloid and Polymer Science 286 ( 5 ) 525 - 534 2008.4

Effect of chain transfer agents on the kinetics and mechanism of particle nucleation in the emulsion polymerization of vinyl pivalate Reviewed

S. Suzuki, K. Kikuchi, A. Suzuki, T. Okaya, M. Nomura

Colloid and Polymer Science 285 523 - 534 2007.11

Effect of chain transfer agents on the kinetics and mechanism of particle nucleation in the emulsion polymerization of vinyl pivalate Reviewed

S. Suzuki, K. Kikuchi, A. Suzuki, T. Okaya, M. Nomura

Colloid and Polymer Science 285 523 - 534 2007.11

Effect of chain transfer agents on kinetics and mechanism of particle nucleation in the emulsion polymerization of vinale acetate Reviewed

S. Suzuki, K. Kikuchi, A. Suzuki, T. Okaya, M. Nomura

Colloid and Polymer Science 285 ( 5 ) 523 - 534 2006.4

Effect of Additives on the Initial Stage of Emulsion Polymerization of styrene (St) using PVA as a Protective Colloid Reviewed

A. Suzuki, Y. Matsuda, K. Kikuchi and T. Okaya

Colloid and Polymer Science 285 ( － ) 193 - 201 2006.4

Influence of additives on the model emulsion polymerizaion of vinyl acete (VAc) using PVA as a protective colloid. Reviewed

A. Suzuki, M. Yano, T. Saiga, K. Kikuchi and T. Okaya

Colloid and Polymer Science 285 ( 2 ) 185 - 192 2006.4

Influence of additives on the model emulsion polymerizaion of vinyl acete (VAc) using PVA as a protective colloid. Reviewed

A. Suzuki, M. Yano, T. Saiga, K. Kikuchi, T. Okaya

Colloid and Polymer Science 285 ( 2 ) 185 - 192 2006.4

Effect of Additives on the Initial Stage of Emulsion Polymerization of styrene (St) using PVA as a Protective Colloid Reviewed

A. Suzuki, Y. Matsuda, K. Kikuchi, T. Okaya

Colloid and Polymer Science 285 ( - ) 193 - 201 2006.4

Effect of chain transfer agents on kinetics and mechanism of particle nucleation in the emulsion polymerization of vinale acetate Reviewed

S. Suzuki, K. Kikuchi, A. Suzuki, T. Okaya, M. Nomura

Colloid and Polymer Science 285 ( 5 ) 523 - 534 2006.4

Unique Magnetic Behavior in the C60 Charge Transfer Complexes Reviewed

Atsushi Suzuki

1995.3

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