1997 Fiscal Year Final Research Report Summary
Control of band offsets qt high-index semi conductor interfaces by the Piezo-effect induced with thin strained insertion layrs
| Project/Area Number |
08650029
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
表面界面物性
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| Research Institution | University of Tokyo |
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Principal Investigator |
SAITO Toshio Univ.of Tokyo, CCR,Reserch Associate, 国際・産学共同研究センター, 助手 (90170513)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAKAWA Kazuo Univ, of Tokyo, IIS,Ass.Professor, 生産技術研究所, 助教授 (10183097)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Gallium Arsenide / Indium Arsenide / Aluminium Arsenide / Ultra Thin Film / Piezo-Effect / Semiconductor Interface / Band Offset / Tight-Binding Method |
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| Research Abstract |
We have theoretically studied the electronic structure of an InAs monolayr on a (311) GaAs substrate by using the semi-empirical sp^3s^<**> tight-binding method. (InAs)_1/(GaAs)_n[311] superlattices with n=10-26 are used for calculations. The (311)-InAs monolayr induces an electron level (near the conduction-band edge) and a hole level (near the valence-band edge) in the GaAs band-gap. The electron-hole energy separation is smaller than the GaAs band-gap energy by 0.06eV (n=10) and 0.03eV (n=26), which accounts for the observed photoluminescence peak [M.I.Alonso et al. : Phys. Rev. B50,1628 (1994)]. The charge densities of the electorn state and the hole state are weakly lacalized near the (311)-InAs monolayr. Next, we have studied the strain energy distribution and electronic structure of InAs pyramidal quantum dots (QDs) with uncovered surfaces. Using the sp^3s^<**> tight-binding method, we calculate the densities of states for the inside states and the surface states. The density of the inside states shows a large energy gap ; 2.71-1.74eV for 161-1222-atom QDs. At the same time, we find the surface states in the gap.
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