Semiconductor Materials Design Lab University of Tsukuba

Scientific Journal Papers


2021

  • "Interface recombination of Cu2ZnSnS4 solar cells leveraged by high carrier density and interface defects" Jianjun Li, Jialiang Huang, Yanchan Huang, Hitoshi Tampo, Takeaki Sakurai, Chao Chen, Kaiwen Sun, Chang Yan, Xin Cui, Yaohua Mai, Xiaojing Hao, Solar RRL, in press.

  • “Study of Defect Properties and Recombination Mechanism in Rubidium Treated Cu(In, Ga)Se2 Solar Cells”, Hamidou TANGARA, Setareh Zahedi-Azad, Jennifer Not, Jakob Schick, Alban Lafuente Sampietro, Muhammad Monirul Islam, Roland Scheer, Takeaki Sakurai, Journal of Applied Physics, in press.

  • "Effect of radio-frequency power on the composition of BiVO4 thin-film photoanodes sputtered from a single target" J. Liu, K. Tajima, I. Abdellaoui, M.M. Islam, S. Ikeda, T. Sakurai, Energies, in press.

  • "Effect of the double grading on the internal electric field and on the carrier collection in CIGS solar cells"A. Lafuente-Sampietro, K. Yoshida, S. Wang, S. Ishizuka, H. Shibata, N. Sano, K. Akimoto, T. Sakurai, Solar Energy Materials and Solar Cells, in press.

  • "Mechanism of Incorporation of Zirconium into BiVO4 Visible-light Photocatalyst" I. Abdellaoui, M.M. Islam, M. Remeika, S. Kanno, R. Okamoto, K. Tajima, S.A. Pawar, Y. Hau Ng, C. Budich, T. Maeda, T. Wada, S. Ikeda,and T. Sakurai, The Journal of Physical Chemistry C, in press.

  • "Identification of deep level defects in CdTe solar cells using transient photo-capacitance spectroscopy" by L. CHUANG, X. Hao, Y. He, J. Zhang, L. Wu, W. Li, W. Wang, L. Feng, M.M. Islam, K. Akimoto, T. Sakurai, Japanese Journal of Applied Physics, in press.

  • "Improvement of power factor in the room temperature range of Mg2Sn1-xGex" M. Lima, T. Aizawa, I. Ohkubo, T. Sakurai, T. Mori, Japanese Journal of Applied Physics, in press.

  • “Study of Open Circuit Voltage Loss Mechanism in Perovskite Solar Cells" Y. He, I. Abdellaoui, M. Abdel-Shakour, T. Chowdhury, M. Kamarudin, A. Nogueira, Q. Shen, S. Hayase, A. Islam, T. Sakurai, Japanese Journal of Applied Physics, in press.

  • "Photo-induced Conductivity Transient in n-type β-(Al0.16Ga0.84)2O3 and β-Ga2O3" A. Traore, M. Gouveia, H. Okumura, C. Mannequin, A. Fassion, T. Sakurai, Japanese Journal of Applied Physics, in press.

  • "Study of ion-implanted nitrogen related defects in diamond Schottky barrier diode by transient photocapacitance and photoluminescence spectroscopy" J. Guo, A. Traore, M. Ogura, M.H. Bakar, S. Yamasaki, E. Gheeraert, T. MAKINO, T. Sakurai, Japanese Journal of Applied Physics, in press.

  • "Carrier Transport Mechanism of Diamond p-i–n Junction at Low Temperature Using Schottky–pn Junction Structure" A. Karasawa, T. MAKINO, A. Traore, H. KATO, M. Ogura, Y. Kato, D. Takeuchi, S. Yamasaki, T. Sakurai, Japanese Journal of Applied Physics rapid communications, in press.


2020

  • “Photocarrier Recombination Dynamics in BiVO4 for Visible Light-Driven Water Oxidation,” I. Abdellaoui, M. M. Islam, M. Remeika, Y. Higuchi, T. Kawaguchi, T. Harada, C. Budich, T. Maeda, T. Wada, S. Ikeda, and T. Sakurai, The Journal of Physical Chemistry C, 124, pp.3962-3972, 2020.

  • “Study of defects in diamond Schottky barrier diode by photocurrent spectroscopy,” J. Guo, A. Traore, M.H. Bakar, T. Makino, S. Yamasaki, M. Ogura, and T. Sakurai, Japanese Journal of Applied Physics, 59, Art.SGGK14, 2020.

  • "Understanding the role of Se in defect reduction in CdTe photovoltaics" C Li, X Hao, J Zhang, L Wu, W Li, W Wang, L Feng, T Sakurai 2020 47th IEEE Photovoltaic Specialists Conference (PVSC), 2649-2651


2019

  • “Fabrication of Mg2Sn(111) film by molecular beam epitaxy,”T. Aizawa, I. Ohkubo, M. Lima, T. Sakurai, and T. Mori, Journal of Vacuum Science and Technology A, 37, Art 061513, 2019.

  • “Study of local structure at crystalline rubrene grain boundaries via scanning transmission X-ray microscopy,” A.L. Foggiatto, Y. Takeichi, K. Ono, H. Suga, Y. Takahashi, M.A. Fusella, J.T. Dull, B.P. Rand, K. Kutsukake, T. Sakurai, Org. Electron., 74, 315 (2019).

  • “Wavelength dependent J-V characteristics of CuIn1-xGax(S,Se)2 solar cells and carrier recombination” A.Lafuente-Sampietro, J.Chen, S.Wang, X.Hao, MM.Islam, T.Kato, H.Sugimoto, K.Akimoto, T.Sakurai Applied Physics Express 12, 061001 (2019).

  • “Dependence of substrate work function on the energy-level alignment at organic–organic heterojunction interface” AL.Foggiatto, H.Suga, Y.Takeichi, K.Ono, Y.Takahashi, K.Kutsukake, T.Ueba, S.Kera. T.Sakurai, Japanese Journal of Applied Physics, 58, SBBG06 (2019).

  • “Investigation of stress at SiO2/4H-SiC interface induced by thermal oxidation by confocal Raman microscopy” Wei Fu, Ai Kobayashi, Hiroshi Yano, Akiko Ueda, Shinsuke Harada, Takeaki Sakurai Japanese Journal of Applied Physics, 58, SBBD03 (2019).



2018

  • Energy Level Alignment at Interfaces in Metal Halide Perovskite Solar Cells S Wang, T Sakurai, W Wen, Y Qi Advanced Materials Interfaces 5, 1800260 (2018)

  • Influence of potassium treatment on electronic properties of Cu (In1 x Ga x)(Se1 y S y) 2 solar cells studied by steady state photo-capacitance and admittance spectroscopy S Wang, X Hao, MM Islam, T Kato, H Sugimoto, K Akimoto, T Sakurai Japanese Journal of Applied Physics 57, 08RC13 (2018)

  • Relationship between bandgap grading and carrier recombination for Cu (In, Ga) Se2-based solar cells, Y Ando, S Ishizuka, S Wang, J Chen, MM Islam, H Shibata, K Akimoto, T Sakurai Japanese Journal of Applied Physics 57, 08RC08 (2018)

  • Impurities removal process for high-purity silica production from diatomite I Abdellaoui, MM Islam, T Sakurai, S Hamzaoui, K Akimoto Hydrometallurgy (2018)

  • Deep level emission in polycrystalline CuGaSe2 thin-films observed by micro-photoluminescence MM Islam, S Wang, S Ishizuka, H Shibata, S Niki, K Akimoto, T Sakurai Japanese Journal of Applied Physics 57, 08RC02 (2018)

  • Electrodeposition and characterization of silicon films obtained through electrochemical reduction of SiO2 nanoparticles MM Islam, I Abdellaoui, C Moslah, T Sakurai, M Ksibi, S Hamzaoui, K.Akimoto, Thin Solid Films 654, 1-10 (2018)

  • Characterization of Defect Properties in Wide-Gap CuGaSe2 Thin-Film Solar-Cells MM Islam, S Ishizuka, H Shibata, S Niki, K Akimoto, T Sakurai Nanoscience and Nanotechnology Letters 10, 559-564 (2018)

  • Depth Profile of Impurity Phase in Wide-Bandgap Cu(In1x,Gax)Se2 Film Fabricated by Three-Stage Process S Wang, T Nazuka, H Hagiya, Y Takabayashi, S Ishizuka, H Shibata, K.Akimoto, T Sakurai Journal of Electronic Materials, 47,4944-4949 (2018)

  • Effects of Zirconium Doping Into a Monoclinic Scheelite BiVO4 Crystal on Its Structural, Photocatalytic, and Photoelectrochemical Properties S Ikeda, T Kawaguchi, Y Highchi, N Kawasaki, T Harada, M Remeika, T Sakurai. Frontiers in chemistry 6, 266 (2018)

  • “Charge transfer induced by MoO3 at boron subphthalocyanine chloride/α-sexithiophene heterojunction interface”. A. L. Foggiatto and T. Sakurai. Japanese Journal of Applied Physics, 57, 03EE01 (2018).

  • “Impact of carrier doping on electrical properties of laser-induced liquid-phase-crystallized silicon thin films for solar cell application”, H.Umishio, T.Matsui, H.Sai, T.Sakurai, K.Matsubara, Japanese Journal of Applied Physics 57, 021302 (2018)



2017

  • “An optimized photolithography recipe for Cu(In1-x,Gax)(Sy,Se1-y)2 (CIGSSe) solar cells”. X. Hao, S. Wang, K. Akimoto, T. Kato, H. Sugimoto, and T. Sakurai. Proceeding of IEEE 44th Photovoltaic Specialists Conference (PVSC), 2017.

  • “Study of defect properties in CuGaSe2 thin-film solar-cells using Admittance Spectroscopy”. M. M. Islam, S. Ishizuka, H. Shibata, S. Niki, K. Akimoto, and T. Sakurai. Proceeding of the IEEE 44th Photovoltaic Specialists Conference (PVSC-44), 2017.

  • “Electrodeposition of Si-layer through reduction of diatomaceous earth for the application of solar-cells”. M. M. Islam, I. Abdellaoui, T. Sakurai, S. Hamzaoui, and K. Akimoto. Proceeding of the IEEE 44th Photovoltaic Specialists Conference (PVSC-44), 2017.


2016

  • Akira Uedono, Muhammad M. Islam, Takeaki Sakurai, Christoph Hugenschmidt, Werner Egger, Roland Scheer, Reinhard Krause-Rehberg, Katsuhiro Akimoto, “Vacancy behavior in Cu(In1-xGax)Se2 layers grown by a three-stage coevaporation process probed by monoenergetic positron beams”, Thin Solid Films 603, (2016) 418-423.

  • Mohammad Abdul Halim, Muhammad Monirul Islam, Xianjia Luo, Takeaki Sakurai, Noriyuki Sakai, Takuya Kato, Hiroki Sugimoto, Hitoshi Tampo, Hajime Shibata, Shigeru Niki, and Katsuhiro Akimoto, “A comparative study on charge carrier recombination across the junction region of Cu2ZnSn(S,Se)4 and Cu(In,Ga)Se2 thin film solar cells”, AIP Advances 6, (2016), 035216.

  • M. Kubota, T. Sakurai, T. Miyadera, H. Nakao, T. Sugita, and Y. Yoshida, "Domain structure and electronic state in P3HT:PCBM blend thin films by soft X-ray resonant scattering", J. Appl. Phys. 120 (2016) 165501.

  • X. Hao, K.T. Chowdhury, T. Sakurai, Y. Kamikawa-Shimizu, S. Ishizuka, A. Yamada, H. Shibata, K. Akimoto, “The Influence of Sodium in High Ga-Content Cu(In1-x,Gax)Se2 (CIGS) Solar Cells”, Proceedings of the 32nd European Photovoltaic Solar Energy Conference and Exhibition, 2016, 3CV.4.17, 1213-1215.

  • 守友浩, 安田剛, 米澤宏平, 櫻井岳暁, “有機デバイスへの応用:ナノ構造と機能性放射光, 29 (2016) 313-319.


2015

  • C. Lin, S. Liu, C. Lee, T. Sakurai, M. Kubota, W. Su, J. Huang, T. Chiu, H. Han, L. Chen, C. Chen and J. Lee. A new anodic buffer layer material for non-mixed planar heterojunction chloroboron subphthalocyanine organic photovoltaic achieving 96% internal quantum efficiency. Solar Energy Materials & Solar Cells, 137 (2015) 138.

  • Y. Moritomo, K. Yonezawa, T. Sakurai, T. Yasuda, Y. Takeichi, H. Kamioka, H. Suga, Y. Takahashi, Y. Yoshida, N. Inami, K. Mase and K. Ono. Morphology of F8T2/PC71BM Blend Film as Investigated by Scanning Transmission X-ray Microscope (STXM). Molecular Crystals and Liquid Crystals, 620 (2015) 32.

  • M. Okano, H. Hagiya, T. Sakurai, K. Akimoto, H. Shibata, S. Niki, and Y. Kanemitsu. Individual identification of free hole and electron dynamics in CuIn1xGaxSe2 thin films by simultaneous monitoring of two optical transitions. Applied Physics Letters, 106 (2015) 181903.

  • Y. Moritomo, T. Yasuda, K. Yonezawa, T. Sakurai, Y. Takeichi, H. Suga, Y. Takahashi, N. Inami, K. Mase and K. Ono, Fullerene mixing effect on carrier formation in bulk-hetero organic solar cell. Scientific report, 5 (2015) 9483.

  • X. B. Hu, T. Sakurai, A. Yamada, S. Ishizuka, S. Niki, and K. Akimoto, Investigation of the properties of deep-level defect in Cu(In,Ga)Se 2 thin films by steady-state photocapacitance and time-resolved photoluminescence measurements. Japanese Journal of Applied Physics, 54 (2015) 04DR02.

  • X. Hao, S. Wang, T. Sakurai and K. Akimoto. Effect of bathocuproine buffer layer in small molecule organic solar cells with inverted structure. Japanese Journal of Applied Physics, 54 (2015), 04DK06.

  • X. Hao, S. Wang, T. Sakurai, S. Masuda and K. Akimoto. Improvement of stability for small molecule organic solar cells by suppressing the trap mediated recombination. ACS Applied Materials & Interfaces, 7 (2015), 18379.

  • M. A. Halim, M. M. Islam, X. Luo, T. Sakurai, N. Sakai, T. Kato, H. Sugimoto, H. Tampo, H. Shibata, S. Niki, and K. Akimoto, Study of time-resolved photoluminescence in Cu2ZnSn(S,Se)4 thin films with different Cu/Sn ratio. Japan Journal of Applied Physics, 54 (2015) 08KC15.

  • N. Komuro, M. Mikami, P. J. Saines, K. Akimoto and A. K. Cheetham, Deep red emission in Eu2+-activated Sr4(PO4)2O phosphors for blue-pumped white LEDs, Journal of Materials Chemistry C, 2015, 3, 7356.

  • M. M. Islam, M. A. Halim, T. Sakurai, N. Sakai, T. Kato, H. Sugimoto, H. Tampo, H. Shibata, S. Niki, and K. Akimoto. Determination of deep-level defects in Cu2ZnSn(S,Se)4 thin-films using photocapacitance method. Applied Physics Letters, 06 (2015) 243905.

  • M. M. Islam, M. A. Halim, C. Joy, X. Luo, T. Sakurai, N. Sakai, T. Kato, H. Sugimoto, H. Tampo, H. Shibata, S. Niki, K. Akimoto. Study of Cu2ZnSn(S,Se)4 thin films for solar cell application. Journal of Physics: Conference Series 596 (2015) 012019.

  • M. M. Islam, A. Yamada, K. Matsubara, S. Niki, T. Sakurai, K. Akimoto, Effect of Se Flux on the Properties of Polycrystalline CuInSe2 Thin Films and Solar cells, Proceedings at European PV Solar Energy Conference and Exhibition (EU PVSEC 2015), Hamburg, Germany, Sep. 14th-18th, 2015, pp. 1246-1248, DOI:10.4229/EUPVSEC20152015-3DV.1.39.

  • M. M. Islam, H .Shibata, K. Matsubara, S. Niki, T. Sakurai, K. Akimoto, Compositional Dependence Photoluminescence Study of Polycrystalline CuGaSe2 Thin Films, Proceedings at 42nd IEEE Photovoltaic Specialists Conference (PVSC), New Orleans, June 14th-19th, 2015, pp. 1-4, DOI:10.1109/PVSC.2015.7355791.

  • M. A. Halim, M. M. Islam, X. Luo, T. Sakurai, N. Sakai, T. Kato, H. Sugimoto, H. Tampo, H. Shibata, S. Niki, K. Akimoto. Electroluminescence study of Cu2ZnSn(S,Se)4 and Cu(In,Ga)Se2 thin film solar cells. Proceedings of the 31st European Photovoltaic Solar Energy Conference and Exhibition (2015) 1074


2014

  • “Investigation of deep-level defects in Cu(In,Ga)Se2 thin films by a steady-state photocapacitance method”, X Hu, T Sakurai, A Yamada, S Ishizuka, S Niki, K Akimoto, Journal of Applied Physics 116, 163703 (2014).

  • “Effect of antimony on the deep-level traps in GaInNAsSb thin films”, MM Islam, N Miyashita, N Ahsan, T Sakurai, K Akimoto, Y Okada, Applied Physics Letters 105, 112103 (2014).

  • “Novel cathode buffer layer of Ag-doped bathocuproine for small molecule organic solar cell with inverted structure”, X Hao, S Wang, W Fu, T Sakurai, S Masuda, K Akimoto, Organic Electronics 15, 1773-1779 (2014).

  • “Investigation of the relative density of deep defects in Cu(In,Ga)Se2 thin films dependent on Ga content by transient photocapacitance method”, X Hu, T Sakurai, A Yamada, S Ishizuka, S Niki, K Akimoto, Japanese Journal of Applied Physics 53, 068008 (2014).

  • “Slow intraband relaxation and localization of photogenerated carriers in CuIn1 x GaxSe2 thin films: Evidence for the existence of long-lived high-energy carriers”, M Okano, Y Takabayashi, T Sakurai, K Akimoto, H Shibata, S Niki, and Y Kanemitsu Physical Review B 89, 195203 (2014).

  • “Molecular mixing in donor and acceptor domains as investigated by scanning transmission X-ray microscopy”, Y Moritomo, T Sakurai, T Yasuda, Y Takeichi, K Yonezawa, H Kamioka, H Suga, Y Takahashi, Y Yoshida, N Inami, K Mase, K Ono, Applied Physics Express, 7, 052302 (2014).

  • “Defect study of Cu2ZnSn(S,Se)4 thin film with different Cu/Sn ratio by admittance spectroscopy”, X Luo, MM Islam, MA Halim, C Xu, T Sakurai, N Sakai, T Kato, H Sugimoto, H Tampo, H Shibata, S Niki, and K. Akimoto, 40th IEEE Photovoltaic Specialist Conference (PVSC), 2366-2369 (2014).

  • “Study of recombination process in Cu2ZnSnS4 thin film using two-wavelength excited photoluminescence, MA Halim, MM Islam, X Luo, C Xu, T Sakurai, N Sakai, T Kato, H Sugimoto, H Tampo, H Shibata, S Niki, and K. Akimoto, 40th IEEE Photovoltaic Specialist Conference (PVSC), 2334-2337 (2014).


2013

  • “Favorable electronic structure for organic solar cells induced by strong interaction at interface” S.Wang, T.Sakurai, X.Hao, W.Fu, S.Masuda, and K.Akimoto, Journal of Applied Physics, 114, Art.183707 (2013).

  • “Investigation of deep-level defects in Cu(In,Ga)Se2 thin films by two-wavelength excitation photo-capacitance spectroscopy” X.Hu, A.Gupta, T.Sakurai, A.Yamada, S.Ishizuka, S.Niki and K.Akimoto, Applied Physics Letters. 103, Art.163905 (2013).

  • “Characterization of Cu(In,Ga)Se2 grown by MBE by two-wavelength excited photoluminescence spectroscopy” A.Gupta, N.Hiraoka, T.Sakurai, A.Yamada, S.Ishizuka, S.Niki, and K.Akimoto, Journal of Crystal Growth, 378, pp. 162-164 (2013).

  • “Effect of Ag-doped bathocuproine on the recombination properties of exciton in fullerene” S.Wang, T.Sakurai, K.Komatsu, K.Akimoto, Journal of Crystal Growth, 378, pp. 415-417 (2013).

  • “Impact of Se flux on the defect formation in polycrystalline Cu(In,Ga)Se2 thin films grown by three stage evaporation process”, M. M. Islam, A. Uedono, T. Sakurai, A. Yamada, S. Ishizuka, K. Matsubara, S. Niki, and K. Akimoto, Journal of Applied Physics, 113, Art.064907 (2013).

  • “Photocapacitance study of MBE grown GaInNAsSb thin film solar cells” M.M.Islam, N.Miyashita, N.Ahsan, T.Sakurai, K.Akimoto, and Y. Okada, Journal of Crystal Growth, 378, pp. 57-60 (2013).

  • "Self-organized InGaAs/GaAs quantum dot arrays for use in high-efficiency intermediate-band solar cells", Yasushi Shoji, Katsuhiro Akimoto, and Yoshitaka Okada, Journal of Physics D: Applied Physics 46, Art.024002 (2013);

  • “A novel synthesis method and up-conversion properties of hexagonal-phase NaYF4:Er nano-crystals”, X.Luo, R.Yuminami, T.Sakurai, K.Akimoto, Journal of Rare Earths, 31, pp. 267-270 (2013).

  • “Effect of Er3+ Concentration on Upconversion in Hexagonal-Phase NaYF4:Er3+ Nanocrystals” X.J Luo, R. Yuminami, T. Sakurai and K. Akimoto, Journal of Physics: Conference Series, 417, Art.012054 (2013).


2012

  • “Identification of defect types in moderately Si-doped GaInNAsSb layer in p-GaAs/n- GaInNAsSb/n-GaAs solar cell structure using admittance spectroscopy”, Muhammad Monirul Islam, Naoya Miyashita, Nazmul Ahsan, Takeaki Sakurai, Katsuhiro Akimoto, and Yoshitaka Okada, J. Appl. Phys. 112, 114910 (2012).

  • “Effect of Er3+ Concentration on Upconversion in Hexagonal-Phase NaYF4:Er3+ Nanocrystals” X.J Luo, R. Yuminami, T. Sakurai and K. Akimoto, J. Phys.: Conf. Ser. 417 012054 (2013).

  • “Energy band bending induced charge accumulation at fullerene/bathocuproine heterojunction interface”, S.Wang, T.Sakurai, R.Kuroda, K.Akimoto, Applied Physics Letters, 100, Art.243302 (2012).

  • “Energy level alignment at interfaces between 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl phenyl)-1, 2, 4-triazole (TAZ) and metals (Ca, Mg, Ag, and Au): experiment and theory”, B.M. Datt, A. Baba, T. Sakurai, K. Akimoto, Journal of Solid State Electrochemistry, 3, pp.1141-1149 (2012).

  • “Hydrogen isotope tracer experiment in a-C:H film deposition: Reactive RF magnetron sputtering with CH4 and D2”, D. Sekiba, N. Takemoto, M. Okada, S. Ishii, T. Sakurai, K. Akimoto, Diamond and Related Materials, 27-28, pp.60-63 (2012).

  • “Energy level alignment of C60/Ca interface with bathocuproine as a interlayer studied by ultraviolet photoelectron spectroscopy”, S.Wang, T.Sakurai, R.Kuroda, H.Kato, K.Akimoto, Japanese Journal of Applied Physics, 51, 10NE32 (2012).


2011

  • “Structural control of organic solar cells based on nonplanar metallophthalocyanine/C60 heterojunctions using organic buffer layers”, T. Sakurai, T. Ohashi, H. Kitazume, M. Kubota, T. Suemasu, K. Akimoto, Organic Electronics, 12 (2011) 966.

  • “Thickness study of Al:ZnO film for application as a window layer in Cu(In1xGax)Se2 thin film solar cell” M.M.Islam, S. Ishizuka, A. Yamada, K. Matsubara, S. Niki, T. Sakurai, K. Akimoto, Applied Surface Science, 257 (2011) 4026.

  • “Effect of Ga/Cu Ratio on Polycrystalline CuGaSe2 Thin Film Solar Cell” M.M. Islam, A. Yamada, T. Sakurai, S. Ishizuka, K. Matsubara, S. Niki, and K. Akimoto, Applied in OptoElectronics, 2011 (2011) 573094.

  • “Cu-dependent phase transition in polycrystalline CuGaSe2 thin films grown by three-stage process” M. M. Islam, A. Yamada, T. Sakurai, M. Kubota, S. Ishizuka, K. Matsubara, S. Niki, and K. Akimoto, Journal of Applied Physics, 110 (2011) 014903.

  • “Time-Resolved Microphotoluminescence Study of Cu(In,Ga)Se2” Japanese Journal of Applied Physics, Takeaki Sakurai, Keiki Taguchi, Monirul Muhammad Islam, Shogo Ishizuka, Akimasa Yamada, Koji Matsubara, Shigeru Niki, Katsuhiro Akimoto, Japanese Journal of Applied Physics, 50 (2011), 05FC01.

  • “Impact of Cu/III ratio on the near-surface defects in polycrystalline CuGaSe2 thin films” Muhammad Monirul Islam, Akira Uedono, Shoji Ishibashi, Kazuki Tenjinbayashi, Takeaki Sakurai, Akimasa Yamada, Shogo Ishizuka, Koji Matsubara, Shigeru Niki, Katsuhiro Akimoto, Applied Physics Letters, 98 (2011) 112105.

  • “Barrier formation at organic-metal interfaces studied by density functional theory” B.M. Datt, S. Suzuki, T. Sakurai, K. Akimoto, Current Applied Physics, 11 (2011) 447-450.

  • “Electronic states at 4,4’-N,N’-dicarbazol-biphenyl (CBP)–metal (Mg, Ag, and Au) interfaces: A joint experimental and theoretical study” B.M. Datt, S. Suzuki, T. Sakurai, K. Akimoto, Current Applied Physics, 11 (2011) 346-352.

  • “Effect of doping on metal doped semiconductor” B.M. Datt, S. Suzuki, T. Sakurai, K. Akimoto, Current Applied Physics, 11 (2011) 188-190.

  • “Determination of Cu(In,Ga)3Se5 defect phase in CIGS material by Rietveld analysis” M.M.Islam, T. Sakurai, S. Otagiri, S. Ishizuka, A. Yamada, K. Sakurai, K. Matsubara, S. Niki, K. Akimoto, Solar Energy Materials and Solar Cells, 95 (2011) 231-234.

  • “Dependence of Se beam pressure on defect states in CIGS solar cells” T. Sakurai, M.M.Islam, H. Uehigashi, A. Yamada, S. Ishizuka, K. Matsubara, S. Niki, K. Akimoto, Solar Energy Materials and Solar Cells, 95 (2011) 227-230.


2010

  •  “Luminescence and energy-transfer mechanisms in Eu3+-doped GaN epitaxial films” S. Higuchi, A. Ishizumi, J. Sawahata, K. Akimoto, Y. Kanemitsu, Physical Review B, 81 (2010) 035207.

  •  “Suppression of concentration quenching of Er-related luminescence in Er-doped GaN” S.Q. Chen, B. Dierre, W. Lee, T. Sekiguchi, S. Tomita, H. Kudo, K. Akimoto, Applied Physics Letters, 96 (2010) 181901.

  • “Interaction of organic semiconductor with low work function metals Ca and K”, B.M. Datt, S. Suzuki, K. Akimoto, Physica B-Condensed Matter., 405, (2010) 3520-3524.

  • “Effect of Surface Structure on Transformation of 4H-SiC by High-Temperature Annealing” Y. Kawada, T. Tawara, S. Nakamura, M. Gotoh, T. Tawara, N. Iwamuro, K. Akimoto, Japanese Journal of Applied Physics, 49 (2010) 101301.

  • “Effect of V/III flux ratio on luminescence properties and defect formation of Er-doped GaN”, Shaoqiang Chen, Akira Uedono, Shoji Ishibashi, Shigeo Tomita, Hiroshi Kudo, Katsuhiro Akimoto, Applied Physics Letters, 96 (2010) 051907.

  • “Influence of gap states on electrical properties at interface between bathocuproine and various types of metals”, Takeaki Sakurai, Susumu Toyoshima, Hikaru Kitazume, Shigeru Masuda, Hiroo Kato, Katsuhiro Akimoto, Journal of Applied Physics, 107 (2010) 043707.

  • “Interaction of bathocuproine with metals (Ca, Mg, Al, Ag, and Au) studied by density functional theory”, Mahesh Datt Bhatt, Shugo Suzuki, Takeaki Sakurai, Katsuhiro Akimoto, Appl. Surf. Sci. 256 (2010) 2661-2667.

  • “Comparative study on structural properties of P3HT and P3HT:PCBM thin films by using synchrotron x-ray diffraction” Takeaki SAKURAI, Toshihiro YAMANARI, Masato KUBOTA,Susumu TOYOSHIMA, Tetsuya TAIMA, Yuji YOSHIDA, Katsuhiro AKIMOTO, Jpn. J. Appl. Phys.,49 (2010) 01AC01.


2009

  • “Interaction of Bathocuproine with Ca and Au Studied by Density Functional Theory”, Mahesh Datt Bhatt, Shugo Suzuki, Takeaki Sakurai, Katsuhiro Akimoto Jpn. J. Appl. Phys.,48 (2009) 125504.

  • “Incorporation sites and luminescence characterizations of Er-doped GaN grown by molecular beam epitaxy” Shaoqiang Chen, Jongwon Seo, Junji Sawahata, Katsuhiro Akimoto,
    Journal of Crystal Growth, 311 (2009) 2042-2045.

  • “Relationship between defects and optical properties in Er-doped GaN” Shaoqiang Chen, Akira Uedono, Jongwon Seo, Junji Sawahata, Katsuhiro Akimoto,
    Journal of Crystal Growth, 311 (2009) 3097-3099.

  • “Level alignment of gap state at organic-metal interface” M. Aoki, S. Toyoshima, T. Kamada, M. Sogo, S. Masuda, T. Sakurai, and K. Akimoto, Journal of Applied Physics, 106 (2009) 043715.

  • “Orientation-controlled phthalocyanine-based photovoltaic cell formed on pentacene buffer layer”, Takeaki Sakurai, Ryusei Naito, Susumu Toyoshima, Tatsuya Ohashi, and Katsuhiro Akimoto,
    Nanoscience and Nanotechnology Letters, 1, (2009) 23-27.

  • “Na-induced variations in the structural, optical, and electrical properties of Cu(In,Ga)Se2 thin films” Shogo Ishizuka, Akimasa Yamada, Muhammad Monirul Islam, Hajime Shibata, Paul Fons,
    Takeaki Sakurai, Katsuhiro Akimoto, and Shigeru Niki, Journal of Applied Physics, 106 (2009) 034908.

  • “CIGS solar cell with MBE-grown ZnS buffer layer” M.M. Islam, S. Ishizuka, A. Yamada, K. Sakurai, S. Niki, T. Sakurai, K. Akimoto, Solar Energy Materials and Solar Cells, 93 (2009) 970-972.

  • “Effect of Se/(Ga+In) ratio on MBE grown Cu(In,Ga)Se2 thin film solar cell” M.M. Islam, T. Sakurai, S. Ishizuka, A. Yamada, H. Shibata, K. Sakurai, K. Matsubara, S. Niki, K. Akimoto,
    Journal of Crystal Growth, 311 (2009) 2212-2214.

  • “Temperature dependence of photocapacitance spectrum for CIGS solar cell” T. Sakurai, H. Uehigashi, M.M. Islam, T. Miyazaki, S. Ishizuka, K. Sakurai, A. Yamada, K. Matsubara, S. Niki, K. Akimoto, Thin Solid Films, 517 (2009) 2403-2406.


2008

  • “Deep level transient spectroscopy of cyanide treated polycrystalline p-Cu2O/n-ZnO solar cell” G.K.Paul, R.Ghosh, S.K.Bera, S.Bandyopadhyay, T.Sakurai, K Akimoto,
    Chem. Phys. Lett., 463 (2008) 117-120.

  • “Improved Contact Resistance in AlGaN/GaN Heterostructures by Titanium Distribution Control at the Metal–Semiconductor Interface” H.Sazawa, Y.Honda, M.Hata, A.Hasegawa,
    H.Hamamatsu, M.Shimizu, H.Okumura, T.Sakurai, K.Akimoto, Applied Physics Express, 1 (2008) 081101.

  • “A low-leakage and reduced current collapse AlGaN/GaN heterojunction field effect transistor with AlOx gate insulator formed by metal-organic chemical vapor deposition” H.Sazawa,
    N.Nishikawa, Y.Honda, M.Hata, S.Yagi, M.Shimizu, H.Okumura, T.Sakurai, K.Akimoto, physica status solidi (c), 5 (2008) 1986-1988.

  • “Molecular Orientation Control of Phythalocyanine Thin Film by Inserting Pentacene Buffer Layer” R.Naito, S.Toyoshima, T.Ohashi, T.Sakurai, K.Akimoto, Jpn. J. Appl. Phys. 47 (2008) 1416-1418.

  • “Ultraviolet Photoemission Study of Calcium Doped Bathocuproine” S.Toyoshima, T.Sakurai, T.Taima, K.Saito, H.Kato, K.Akimoto, Jpn. J. Appl. Phys. 47 (2008) 1397-1399.

  • “Vacancy-type defects in Er-doped GaN studied by a monoenergetic positron beam”, A. Uedono, C. Shaoqiang, S. Jongwon, K. Ito, H. Nakamori, N. Honda, S. Tomita, K. Akimoto, and H. Kudo, Journal of Applied Physics, 103 (2008) 104505.

  • “Structural characterization of Eu-doped GaN by transmission electron microscopy” J.Seo, S.Chen, J.Sawahata, M. Mitome, K.Akimoto, Journal of Ceramics Processing Research, 9 (2008) 68-70.

  • “Photoluminescence spectra of Eu-doped GaN” J.Sawahata, J.Seo, S.Chen, K.Akimoto, physica status solidi (a), 205 (2008) 71-74.

  • “Site-dependent Eu3+ luminescence in GaN : Eu3+ epitaxial films studied by microscopic photoluminescence spectroscopy” A.Ishizumi, J.Sawahata, K.Akimoto, Y.Kanemitsu, Mater. Sci. Eng. B , 146 (2008) 186-188.


2007

  • “Effects of annealing under various atmospheres on electrical properties of Cu(In,Ga)Se2 films and CdS/Cu(In,Ga)Se2 heterostructures” T.Sakurai, N.Ishida, S.Ishizuka, M.D.Islam, A.Kasai, K.Matsubara, K.Sakurai, A.Yamada, K.Akimoto, and S.Niki, Thin Solid Films, 516 (2008) 7036-7040.

  • “Control of molecular orientation of organic p-i-n structures by using molecular templating effect at heterointerfaces” T.Sakurai, R.Fukasawa, K.Saito, K.Akimoto, Organic Electronics 8 (2007) 702-708.

  • “Effects of V/III ratio on photoluminescence spectra of Eu-doped GaN grown by molecular beam epitaxy” J.Sawahata, J.Seo, M.Takiguchi, D.Saito, S.Nemoto, K.Akimoto, J. Cryst. Growth 301(2007) 420-423.

  • “Electronic Structure of Bathocuproine on Metal Studied by Ultraviolet Photoemission Spectroscopy”, Susumu Toyoshima, Kazuhisa Kuwabara, Takeaki Sakurai, Tetsuya Taima, Kazuhiro Saito, Hiroo Kato, and Katsuhiro Akimoto, Jpn. J. Appl. Phys. 46 (2007) 2692-2695.

  • “Investigation of relation between Ga concentration and defect levels of Al/Cu(In,Ga)Se2 schottky junctions using admittance spectroscopy” T.Sakurai, N.Ishida, S.Ishizuka, K.Matsubara, K.Sakurai, A.Yamada, G.K.Paul, K.Akimoto, S.Niki, Thin Solid Films 515 (2007) 6208-6211.


2006

  • "Growth process of phthalocyanine films deposited on 3,4,9,10-perylene tetracarboxylic dianhydride template layers", T. Sakurai, R. Fukasawa, and K. Akimoto, Jpn. J. Appl. Phys., 45 (2006) 255-259.

  • "Structural and optical properties of phthalocyanine thin films grown on glass with 3,4,9,10-perylene tetracarboxylic dianhydride intermediate layer", T. Sakurai, R. Fukasawa, S. Kawai, and K. Akimoto, Jpn. J. Appl. Phys., 45 (2006) 397-400.

  • "TEM observation of Eu-doped GaN and fabrication of n-GaN/Eu:GaN/p-GaN structure", J. Sawahata, H. Bang, J. W. Seo, T. Tsukamoto, and K. Akimoto, Optical Materials, 28 (2006) 759-762.

  • "Effect of V/III ratio on the optical properties of Eu-doped GaN", J. Sawahata, J. W. Seo, M. Takiguchi, D. Saito, S. Nemoto, and K. Akimoto, phys. status solidi (c) 3 (2006) 1911-1914.

  • "Photoluminescence spectra of Eu-doped GaN with various Eu concentrations", J. Sawahata, J. W. Seo, S. Chen, M. Takiguchi, D. Saito, S. Nemoto, and K. Akimoto, Appl. Phys. Lett. 89 (2006) 192104.

  • "Origin of efficient luminescence from GaN:Eu3+ epitaxial film revealed by microscopic photoluminescence imaging spectroscopy", A. Ishizumi, J. Sawahata, K. Akimoto, and Y. Kanemitsu, Appl. Phys. Lett. 89 (2006) 191908.

  • "Ellipsometric study of an organic template effect: H2Pc/PTCDA",O. D. Gordan, T. Sakurai, M. Friedrich, K. Akimoto, and D. R. T. Zhan, Organic Electronics 7 (2006) 521-527.

  • "Defects in Cu2O studied by deep level transient spectroscopy", G. K. Paul, Y. Nawa, H. Sato, T. Sakurai, and K. Akimoto, Appl. Phys. Lett., 88 (2006) 141901.

  • "Thin film deposition of Cu2O and application for solar cells", K. Akimoto, S. Ishizuka, M. Yanagita, Y. Nawa, G. K. Paul, T. Sakurai, Solar Energy, 80 (2006) 715-722.

  • "Study on electrical properties of Al/Cu(In,Ga)Se2 Schottky junction and ZnO/CdS/Cu(In,Ga)Se2 heterojunction using admittance spectroscopy", T. Sakurai, N. Ishida, S. Ishizuka, K. Matsubara,K. Sakurai, A. Yamada, G. K. Paul, K. Akimoto, and S. Niki, phys. status solidi (c) 3 (2006) 2576-2580.


Scientific Books (in Japanese)

  •  “CIGS太陽電池の最先端技術 53 電気的手法によるCIGS太陽電池の欠陥評価櫻井岳暁、秋本克洋(分担執筆)、CMC出版、(2010年)

  • 有機薄膜太陽電池の高効率化と耐久性向上 63 有機/無機界面の物性評価櫻井岳暁、秋本克洋(分担執筆)、サイエンス&テクノロジー(20091月)

  • 発光と受光の物理と応用 63 希土6類添加半導体発光デバイス秋本克洋(分担執筆)、培風館(20083月)

  • 化合物薄膜太陽電池の最新技術 33 CIGS太陽電池の電子物性評価櫻井岳暁、秋本克洋(分担執筆)、CMC出版、(20076月)