Researchers

Nagai Takehiko

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

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

表面・界面物性, 光物性, 光電子分光

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
Cu2O single crystal growth using CuCl flux and bandgap evaluation
Fumio Kawamura; Takehiko Nagai; Hitoshi Tampo
Materials Letters 365 15, Jun. 2024
Tunability of the bandgap of SnS by variation of the cell volume by alloying with A.E. elements
Fumio Kawamura; Yelim Song; Hidenobu Murata; Hitoshi Tampo; Takehiko Nagai; Takashi Koida; Masataka Imura; Naoomi Yamada
Scientific Reports 12 (1) , 7434-, May. 2022 , Refereed

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
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:  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>
[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