Researchers

Nagai Takehiko

Nagai Takehiko
Professor
Faculty Department of Electronic Engineering and Computer Science
Researchmap https://researchmap.jp/read0120078

Research Activities

Research Areas

  • Nanotechnology/Materials , Basic physical chemistry
  • Nanotechnology/Materials , Thin-film surfaces and interfaces
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) , Electric/electronic material engineering

Research Interests

表面・界面物性, 光物性, 光電子分光

Published Papers

  1. Deep learning ellipsometry: Ultrafast and high-accuracy determination of optical constants, film structures, and bandgaps
    Ryosuke Oka; Yuki Yamamoto; James N. Hilfiker; Takuji Maekawa; Hitoshi Tampo; Takehiko Nagai; Hiroyuki Fujiwara
    Materials Today Communications  48  , 113448-113448, Sep. 2025  , Refereed
  2. Cu2O single crystal growth using CuCl flux and bandgap evaluation
    Fumio Kawamura; Takehiko Nagai; Hitoshi Tampo
    Materials Letters  365  15, Jun. 2024  , Refereed
  3. Fabrication of the bandgap-tuned alkaline earth-alloyed SnS solar cell
    Fumio Kawamura; Yelim Song; Hidenobu Murata; Hitoshi Tampo; Takehiko Nagai; Takashi Koida; Jaeeun Jeon; Masataka Imura; Naoomi Yamada
    Journal of the Ceramic Society of Japan  131  (10)  , 708-711, 1, Oct. 2023  , Refereed

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MISC

  1. Excitons and electron-hole plasmas in highly excited GaN , T. Nagai; T. J. Inagaki; Y. Kanemitsu , Physica Status Solidi C: Conferences , 1 , 495 , 498 , Dec. 2020
  2. Measurement for Silane Density in Silane-Hydrogen Gas Mixtures Using a Quartz Sensor , SUZUKI Atsushi; KARASAWA Minoru; NAGAI Takehiko; NONAKA Hidehiko; KONDO Michio , Journal of the Vacuum Society of Japan , 53 , 3 , 162 , 164 , 20, Mar. 2010
    Summary:&nbsp;&nbsp;Densities of silane and hydrogen gas mixtures used for the production of thin silicon solar cell were measured using a quartz sensor, which output depends on viscosity and molecular weight of gas measured. The measurement for the silane-hydrogen gas mixtures revealed that the quartz sensor output depends on the silane and hydrogen densitites, can derive each density in the mixtures. From the results of the measurement, working curves were dereived for the pressure of 133-1333.0 Pa for the industrial production at room temperature. Resolusions of the density measured are 0.03 vol.% at total pressure of 1333.0 Pa, and are comparable to the results by a quartz pressure gauge previously reported. Finally, it was shown that the silane density ratio does not agree with the silane flow ratio, indicating that <i>in-situ</i> silane density measurement is important to control silane density.<br>
  3. [高圧ガス]用語解説 量子ドット型太陽電池 , 永井 武彦 , 高圧ガス , 46 , 8 , 651 , 651 , Aug. 2009

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Research Grants & Projects

  1. Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Development of novel functional semiconductor thin films using high pressure annealing , National Institute for Materials Science
  2. 日本学術振興会, 科学研究費助成事業, 有効配位数変調による半導体バンド構造の新しい制御軸構築 , 国立研究開発法人産業技術総合研究所
  3. 日本学術振興会, 科学研究費助成事業, 多元系エピタキシャル半導体薄膜を用いた多様な欠陥の評価と制御 , 国立研究開発法人産業技術総合研究所