Study of recombiration-induced atomic processes associated with deep level in compound semicmductors by meano of cascade excitation spectroscopy

Research Project

Project/Area Number	60540202
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	固体物性
Research Institution	Nagoya University
Principal Investigator	TANIMURA Katsumi Nagoya University, Faculty of Science, 工学部, 助手 (00135328)
Co-Investigator(Kenkyū-buntansha)	NAKAYAMA Takeyoshi Kinki University, Faculty of Science and Technology, 理工学部, 助教授 (60023313)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥700,000 (Direct Cost: ¥700,000)
Keywords	compound semiconductors / deep level / non-radiative recombination / extrinsic self-trapped exciton / 格子緩和 / 原子過程
Research Abstract	Electron-hole recombination process folling pulsed electronic excitation in n-type GaP has been studied by measn of time-resolved optical techniques including absorption and luminescence measurements, photoelastic dilatation measurements and cascade excitation spectroscopy. A mid-gap luminescence band situating at 1.53 eV with a fullwidth at half maxima of 0.25 eV is induced, as well as luminescence due to donor-acceptor recombination. The mid-gap luminescence decays exponentially, indicating that it is emitted by a transition within a localized center. The formation of the state responsible for this luminescence is associated with large lattice distortion of a tenth of molecular volume, which was determined by a direct measurement of the transient volume change. The fomation yield of the center show a saturation for the excitation density of <10^(18)> <cm^(-3)> , and the estimated maximum concentration of the center is about <10^(17)> <cm^(-3)> . Thus the center is apparently related to imperfections existing in specimen prior irradiation. The result observed can only be interpreted in terms of exitsinsic self-trapped exciton.