1996 Fiscal Year Final Research Report Summary
STUDY ON GROWTH AND MATERIAL PROPERTIES OF METASTABLE NITRIDE ALLOY SEMICONDUCTORS
| Project/Area Number |
06452107
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
ONABE Kentaro GRADUATE SCHOOL OF ENGINEERING,THE UNIVERSITY OF TOKYO PROFESSOR, 大学院・工学系研究科, 教授 (50204227)
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| Co-Investigator(Kenkyū-buntansha) |
YAGUCHI Hiroyuki GRADUATE SCHOOL OF ENGINEERING,THE UNIVERSITY OF TOKYO RESEARCH ASSOCIATE, 大学院・工学系研究科, 助手 (50239737)
KONDO Takashi GRADUATE SCHOOL OF ENGINEERING,THE UNIVERSITY OF TOKYO RESEARCH ASSOCIATE, 大学院・工学系研究科, 助手 (60205557)
OSADA Toshihito RESEARCH CENTER OF ADVANCED SCIENCE AND TECHNOLOGY,THE UNIVERSITY OF TOKYO ASSOC, 先端科学技術研究センター, 助教授 (00192526)
SHIRAKI Yasuhiro RESEARCH CENTER OF ADVANCED SCIENCE AND TECHNOLOGY,THE UNIVERSITY OF TOKYO PROFE, 先端科学技術研究センター, 教授 (00206286)
ITO Ryoichi GRADUATE SCHOOL OF ENGINEERING,THE UNIVERSITY OF TOKYO PROFESSOR, 大学院・工学系研究科, 教授 (40133102)
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| Project Period (FY) |
1994 – 1996
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| Keywords | NITRIDE ALLOY SEMICONDUCTOR / GaPN ALLOY / WIDEGAP COMPOUND SEMICONDUCTOR / METASTABLE ALLOY SEMICONDUCTOR / GALLIUM PHOSPHIDE / GALLIUM NITRADE / METALORGANIC VAPOR PHASE EPITAXY / MOVPE |
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| Research Abstract |
Growth and material properties of nitride alloy semiconductors of the type III-V-N,where GaPN alloy is the representative, have been investigated. This group of alloy semiconductors had been hard to grow due to their extreme immiscibility. The present research project achieved the following major results, which will lead to new technological applications.
1.Growth of GaPN Alloys : The growth characteristics of GaPN alloy by metalorganic vapor phase epitaxy using dimethylhydrazine have been clarified. The alloy composition is much affected by the desorption of N atom species from growing surface. Based on these growth characteristics, GaPN alloys with the N concentration as much as 6% have been successfully attained.
2.The Origin and Property of Radiative Levels : From optical measurements and analyzes like absorption, photoluminescence and excitation spectroscopies, the radiative levels have been found to originate from the quasi-localized levels formed in the density-of-states tails at the band edge. The relaxation process of excited carriers at low temperatures is governed by the radiative transitions via N-N pair levels for N concentrations below 1%, and by the relaxation to nonradiative and then to quasi-localized radiative levels for the N concentrations above 1%.
3.Evolution of Band Edge with Increasing N Concentration : It has been that the band edge of GaPN alloys originates from the isolated-N levels in the host GaP crystal. The behavior of mobility edge for quasi-localized excitons has been clarified. These findings are much consistent with a theoretical calculation for the energy bands based on the tight-binding method, and suggest that the huge bowing in the composition dependence of the GaPN energy gap is an intrinsic property of GaPN as well as other related nitride alloys such as GaAsPN and InGaPN.
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