| Project/Area Number |
62540234
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Niigata University |
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Principal Investigator |
KATAYAMA Shin'ichi General Education Department, Niigata University, Associate Professor, 教養部, 助教授 (30018270)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | Semiconductor superlattice / Raman scattering / Lattice vibration / Optical phonons / 表面空乏層 / 半導体格子 / 薄膜 |
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| Research Abstract |
1. Introduction
Recent advance of thin-film growth techniques has enable us to fabricate new man-made semiconductor superlattices. From lattice dynamical aspects, raman scattering experiments have revealed new properties, such as optical phonon confinement, zone-folding effects on the acoustic dispersion, and existence of the interface modes. In the present research program, we explore the longitudinal optical (lo) phonons in superlattices and thin surface layer by calculating the raman spectra. We also study the two-dimensional electronic properties which are affected much by phonons via electron-phonon interactions.
2. Results and Discussions
Our results for the Raman spectra by the LO phonons in GaAs-AL_xGa_<1-x>As superlattices provide a good description of the observed raman profile. The raman intensity associated with the confined lo phonons are related with the thickness of layers which constitute the superlattices. The important effects of phonon damping on raman spectra are discussed by taging into account the increase of damping due to potential fluctuations in alloy AlGaAs layer. Analysis of Raman spectra from P-type GaAs have also revealed the contribution from the surface LO phonons to whole spectra.
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