1991 Fiscal Year Final Research Report Summary
Research of Localized States in Alloy Semiconductors at low Temperatute Under High Pressures
| Project/Area Number |
01490001
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | Hokkaido University |
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Principal Investigator |
NAKAHARA Jun'ichiro Hokkaido University, Science, Associate Professor, 理学部, 助教授 (30013527)
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| Project Period (FY) |
1989 – 1991
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| Keywords | ALLOY SEMICONDUCTORS / SEMIMAGNETIC SEMICONDUCTORS / LOCALIZED STATES / Mn / LATTICE DISTORTION / RELAXATION / InGap / 圧力 |
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| Research Abstract |
The phonon modes in In_<1-X>Ga_XP were investigated under high pressure by Raman scattering spectroscopy. In In_<1-X>Ga_XP a pressure induced structure was observed between LO and TO modes. The origin of this structure is discussed by means of dielectric analysis, pressure dependence, and composition dependence. We conclude that a part of the high energy side of this additional structure is caused by a disorder-activated zone boundary optical phonon. We have done a systematic investigation of photoluminescence (PL) in Cd_<1-X>Mn_XTe of various x. For the photoluminescence near 2eV of Mn^<2+> internal d-d transition, we determined the phonon energy, Huang-Rhys factor and inhomogeneous broadening. But there is discrepancy between this model and the observations above 80K. The temperature dependences of the half width and Stokes shifts of Mn^<2+> indicate that the lattice distortion of excited Mn^<2+> becomes gradually smaller increasing temperature above 80K and is large at low temperatures. For the photoluminescence near 1.15 eV we determined the phonon energy, Huang-Rhys factor and inhomogeneous broadening similarly as Mn^<2+> internal d-d transition. By the temperature dependence of these PL's intensities, we propased the possibility of large lattice distortion induced by Mn^<2+> internal d-d excitations and the existence of different charged states.
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