論文 - 鈴木 秀俊
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Fukuyama A., Aihara T., Yokoyama Y., Kojima M., Fujii H., Suzuki H., Sugiyama M., Nakano Y., Ikari T.
Physica Status Solidi (A) Applications and Materials Science 211 ( 2 ) 444 - 448 2014年2月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Physica Status Solidi (A) Applications and Materials Science
Effect of an internal built-in electric field on the non-radiative recombination process of strain-balanced InGaAs/GaAsP multiple quantum wells (MQWs) inserted into a GaAs p-i-n solar cell structure was investigated using the piezoelectric photo-thermal technique. From the experimental data obtained from two types of p-i-n solar cell structures with partly charge-neutral and uniform-gradient potentials, the decrease in the built-in electric field contributed to the decrease in the non-radiative carrier recombination in the MQW. This phenomenon was especially pronounced in the higher photon energy of the incident light and in large quantum well stack number. With the increase in the photon energy, the penetration length shortened, and most carriers were generated in the charge-neutral area in the i-region. The present experimental results could be understood by the increase in the radiative recombination processes within the MQW because of the wave function overlap is essentially unity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Effects of nitrogen precursor on the Au-assisted vapor–liquid–solid growth of GaAs(N) nanostructures 査読あり
Hidetoshi Suzuki, Kentaro Sakai, Tomohiro Haraguchi, Toshihiro Yamauchi, Masanobu Hijii, Kouji Maeda, Tetsuo
Journal of Crystal Growth 386 100 - 106 2014年1月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Ding W., Fukuyama A., Morioka G., Suzuki A., Suzuki H., Yamaguchi M., Ikari T.
Energy Procedia 60 ( C ) 63 - 70 2014年
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：Energy Procedia
© 2014 The Authors. To investigate the microstructure of nitrogen-induced localized state (EN) that perturbs the conduction band of GaAs host material, we adopted the photoreflectance measurements to chemical-beam-epitaxy and flow-rate modulated chemical-beamepitaxy grown GaAsN thin films. We measured both two split subbands to estimate correct values of EN. It was clearly seen that estimated EN decreased with increasing nitrogen content and temperature. By considering a change of a mean distance between adjacent nitrogen atoms, we concluded that the microscopic structure of EN is not only an isolated nitrogen atom but also nitrogen-related complex, accompanied by low-order pairs of nitrogen atoms and/or nitrogen clusters.
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Nitrogen-induced localized level observed by photoreflectance in GaAsN thin films grown by chemical beam epitaxy 査読あり
Hidetoshi Suzuki, Akio Suzuki, Atsuhiko Fukuyama, Tetsuo Ikari
Journal of Crystal Growth 384 5 - 8 2013年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Phtotovoltaic systems in university of Miyazaki
Yoshino K., Nishioka K., Fukuyama A., Suzuki H., Otsubo M.
Applied Mechanics and Materials 372 555 - 558 2013年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Applied Mechanics and Materials
We organized a project of solar cells in University of Miyazaki in order to develop the technologies for solar cells. We have four kinds PV module systems, such as hybrid Si Thin film (1 kW), Poly-Si (50 kW), CIS (100 kW) and CPV (14 kW×2). Their total is 179 kW. These take appoximately 5% of total electricity of the university. © (2013) Trans Tech Publications, Switzerland.
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Misfit dislocation anisotropies in the InGaAs/GaAs(001) interface measured using X-ray topography and reciprocal space mapping 査読あり
Hidetoshi Suzuki, Takuya Matsushita, Masahiro Katayama, Kouji Maeda, Tetsuo Ikari
Japanese Journal of Applied Physics 53 018001 2013年10月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Reduction of rotational twin formation by indium pre-evaporation in epitaxially grown GaAs films on Si (111) substrate 査読あり
Hidetoshi Suzuki, Daiki Ito, Atsuhiko Fukuyama, Tetsuo Ikari
Jornal of Crystal Growth 380 148 - 152 2013年10月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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原料供給シーケンスの違いが原子層エピタキシー法によるGaAsN薄膜成長に与える影響
芳賀 章博, 貞任 萌, 原口 智宏, 鈴木 秀俊, 福山 敦彦, 尾関 雅志, 碇 哲雄
宮崎大學工學部紀要 42 27 - 30 2013年8月
記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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Si(111)表面へのIII族供給によるGaAs薄膜中の回転双晶軽減
伊東 大樹, 太刀掛 弘晃, 鈴木 秀俊, 福山 敦彦, 碇 哲雄
宮崎大學工學部紀要 42 19 - 22 2013年8月
記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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逆格子マッピングによる成長初期のInGaAs/GaAs(001)界面のミスフィット転位の解析
松下 卓哉, 高比良 潤, 境 健太郎, 前田 幸治, 鈴木 秀俊
宮崎大學工學部紀要 42 85 - 88 2013年8月
記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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III-V-N materials for super-high efficiency multi junction solar cells 査読あり
Ikeda K., Yamaguchi M., Bouzazi B., Suzuki H., Kojima N., Ohshita Y.
Japanese Journal of Applied Physics 52 ( 8 PART 2 ) 08JH11 - 08JH11-4 2013年8月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Japanese Journal of Applied Physics
The majority and minority carrier traps in GaAsN grown by chemical beam epitaxy (CBE) and their relationships with the electrical properties of the materials and solar cells are presented. By adopting a new flow-rate modulation CBE (FM-CBE) method, a higher mobility and a longer minoritycarrier lifetime than those obtained by other growth methods have been achieved. We have characterized deep levels in grown GaAsN films by deep-level transient spectroscopy (DLTS). As a result, we found that 1) a hole trap H2 center (Ev + 0:15 eV) in p-GaAsN acts as an acceptor state and correlates with N concentration, 2) an electron trap E2 (Ec 0:33 eV) center in n-GaAsN and p-GaAsN is a non-radiative recombination center and 3) a hole trap H1 center (Ev + 0.052 eV) newly observed in p-GaAsN acts as an acceptor state and a radiative recombination center. Although further analyses are required, it is very important to reduce the E1 defect density in (In)GaAsN to understand the degradation mechanism of the CBE-grown (In)GaAsN solar cell property and realize a higher efficiency. © 2013 The Japan Society of Applied Physics.
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Effects of gas-flow sequences on the self-limiting mechanisms of GaAsN films grown by atomic layer epitaxy 査読あり
Hidetoshi Suzuki, Hajime Sadato, Tomohiro Haraguchi, Toshihiro Yamauchi, Masashi Ozeki, Tetsuo Ikari
Thin Solid Films 540 79 - 83 2013年7月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Honda Takahiko, Ikeda Kazuma, Inagaki Makoto, Suzuki Hidetoshi, Kojima Nobuaki, Ohshita Yoshio, Yamaguchi Masafumi
Jpn J Appl Phys 52 ( 5 ) 59201 - 059201-1 2013年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：The Japan Society of Applied Physics
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Acceptor Levels due to a Complex Including the Nitrogen–Hydrogen Bond in GaAsN Films Grown by Chemical Beam Epitaxy 査読あり
Hidetoshi Suzuki, Atsuhiko Fukuyama, Tetsuo Ikari
Japanese Journal of Applied Physics 52 052001-1 - 052001-5 2013年3月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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In situ three-dimensional X-ray reciprocal-space mapping of GaAs epitaxial films on Si(001) 査読あり
Takahasi M., Nakata Y., Suzuki H., Ikeda K., Kozu M., Hu W., Ohshita Y.
Journal of Crystal Growth 378 34 - 36 2013年2月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Crystal Growth
The molecular-beam epitaxial growth processes of GaAs on Si(001) were investigated using in situ synchrotron X-ray diffraction. Three-dimensional X-ray intensity distributions around the Si and GaAs 022 Bragg points in reciprocal space were measured during growth using combination of an area detector and one-axis scans. During the initial stage of growth, the average radius of GaAs islands was found to follow a second power law function of the growth time, in accordance with the growth being limited by the binding of Ga with As at step edges. With increasing GaAs thickness, streaky scattering extending from the GaAs 022 peak in the < 111 > directions was observed, indicating the development of plane defects. © 2013 Elsevier B.V. All rights reserved.
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Real-time observation of crystallographic tilting ingaas layers on GaAs offcut substrates 査読あり
Nishi T., Sasaki T., Ikeda K., Suzuki H., Takahasi M., Shimomura K., Kojima N., Ohshita Y., Yamaguchi M.
AIP Conference Proceedings 1556 14 - 17 2013年
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：AIP Conference Proceedings
© 2013 AIP Publishing. In situ X-ray reciprocal space mapping during In x Ga 1-x As/GaAs(001) MBE growth is performed to investigate effects of substrate misorientations on crystallographic tilting. It was found that evolution of the crystallographic tilt for the InGaAs films is strongly dependent on both layer structures and substrate misorientations. We discuss these observations in terms of an asymmetric distribution of dislocations.
DOI： 10.1063/1.4822188
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Suzuki H., Sasaki T., Takahasi M., Ohshita Y., Yamaguchi M.
Materials Science Forum 725 89 - 92 2012年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Materials Science Forum
The effects of In incorporation on anisotropies in the strain relaxation mechanisms of InGaAs on GaAs systems are investigated using a three-dimensional reciprocal space mapping (3D-RSM) technique. Relaxation processes are classified as belonging to one of the following four phases: no relaxation, gradual relaxation, rapid relaxation, and relaxation saturation. Anisotropies appear in the gradual relaxation phase and almost disappear in the rapid relaxation phase. These anisotropies are enhanced by In content. When In content is low, both α- and β-misfit dislocations (MDs) are observed at the same thickness; the density of α-MDs increases more rapidly than that of β-MDs. When In content is high, only β-MDs appear in the gradual relaxation phase. These results suggest that In atoms prevent nucleation and/or gliding of β-MDs. © (2012) Trans Tech Publications, Switzerland.
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Kashima K., Fukuyama A., Nakano Y., Inagaki M., Suzuki H., Yamaguchi M., Ikari T.
Materials Science Forum 725 93 - 96 2012年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Materials Science Forum
The temperature dependences of the piezoelectric photo-thermal (PPT) signals from unintentionally doped p-type GaAsN films grown on semi-insulating GaAs substrate were measured in the temperature range from 80 to 300 K. From the theoretical analysis based on the rate equation for the recombination of photo excited carriers to the localized levels, we identified five hole traps. Among them, estimated concentrations of the two traps increased with increasing the nitrogen contents. Therefore, we concluded that these two traps were due to nitrogen-related levels in GaAsN. © (2012) Trans Tech Publications, Switzerland.
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III-V-N materials for super high-efficiency multijunction solar cells
Yamaguchi M., Bouzazi B., Suzuki H., Ikeda K., Kojima N., Ohshita Y.
AIP Conference Proceedings 1477 24 - 27 2012年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：AIP Conference Proceedings
We have been studying concentrator multi-junction solar cells under Japanese Innovative Photovoltaic R & D program since FY2008. InGaAsN is one of appropriate materials for 4- or 5-junction solar cell configuration because this material can be lattice-matched to GaAs and Ge substrates. However, present InGaAsN single-junction solar cells have been inefficient because of low minority-carrier lifetime due to N-related recombination centers and low carrier mobility due to alloy scattering and non-homogeneity of N. This paper presents our major results in the understanding of majority and minority carrier traps in GaAsN grown by chemical beam epitaxy and their relationships with the poor electrical properties of the materials. © 2012 American Institute of Physics.
DOI： 10.1063/1.4753825
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Suzuki H., Sasaki T., Yamamoto S., Ohshita Y., Fukuyama A., Yamaguchi M.
Materials Science Forum 725 85 - 88 2012年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Materials Science Forum
Anisotropies in misfit dislocations (MDs) at the InGaAs/GaAs(001) interface are investigated by monochromatic X-ray topography (XRT). In the XRT image, white lines with different width are observed. These lines are related to a single MD line or several MD lines (MD bunching). The distribution, density, and number of MDs in one MD bunch are evaluated. The density of α-MDs is higher than that of β-MDs. The MDs in one MD bunch distribute with two peaks in both in-plane directions. In a macroscopic view, the a-MD bunching lay more orderly than the α-MD bunching, whereas in a microscopic view, β-MDs gather in a range narrower than p-MDs. © (2012) Trans Tech Publications, Switzerland.