1993 Fiscal Year Final Research Report Summary
| Project/Area Number |
04452175
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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 |
電子材料工学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SASAKI Akio KYOTO UNIV., DEPT.OF ELEC.ENGRG., PROFESSOR, 工学部, 教授 (10025900)
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| Co-Investigator(Kenkyū-buntansha) |
WAKAHARA Akihiro KYOTO UNIV., DEPT.OF ELEC.ENGRG., ASSIST.PROFESSOR, 工学部, 助手 (00230912)
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| Project Period (FY) |
1992 – 1993
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| Keywords | super lattice / luminescence / disoredering / III-V semiconductors / silicon・germanium / localized level |
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| Research Abstract |
A new semiconductor was proposed in 1989 which is featured by showing both the amorphous-like and the single-crystal-like properties. The proposed semiconducting materials are constructed either artificially or naturally so that chemical composition is disordered but physical alignment is sufficiently ordered for epitaxial growth to be possible. A disordered superlattice (d-SL) is an example of the proposed semiconductors. It was fabricated by changing individual layr widths disorderely in AlAs/GaAs superlattice. New optical and luminescence properties have been experimentally demonstrated in previous studies.
In this study, the d-SLs of Al_xGa_<1-x>As/GaAs, AlAs/Al_yGa_<1-y>As, AlP/GaP,and Si_<1-x>Ge_x/Si were fabricated. The following new properties have been observed.
(1) The luminescence intensity of the d-SL decays less with increasing temperature as compared with that of the ordered superlattice (o-SL) and the bulk alloy (b-AL) with the same chemical composition as the d-SL.The dis
… More
ordering effects were investigated with changing the Al composition, i.e., the energy band difference.
(2) The effects depend proportionally on the band difference and thus become maximum at the AlAs/GaAs d-SL.
(3) A good quality of the interface between AlP and GaP was obtained with using tertialybutylphosphine aand etching GaP substrate in (NH_4) S_x.
(4) Photoluminescence (PL) intensities from the AlP/GaP d-SLs are 110-150 times stronger than those from the o-SLs and the b-AL at 9K.
(5) PL intensities from the Si_<0.76>Ge_<0.24>/Si are several times stronger than those from the o-SLs and the b-AL at 10K.These results show that artificial disordering enhances effectively luminescent capability of the indirect-transition type of semiconductors such as AlP,GaP,Si, and Ge.
The disordered effects were not satisfactorily created, since a large band difference cannot be taken due to the lattice mismatch. This would be improved with surfactan epitaxy. The d-SLs will be applied to luminescence devices in the further study. Less
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