1999 Fiscal Year Final Research Report Summary
STUDY OF EXCITONIC PROPETIES OF LOW-DIMENSINAL ZnO
| Project/Area Number |
10650024
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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 |
Applied materials science/Crystal engineering
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| Research Institution | Ishinomaki Senshu University |
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Principal Investigator |
YASUDA Takashi ISHINOMAKI SENSHU UNIVERSITY, 理工学部, 助教授 (90182336)
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| Co-Investigator(Kenkyū-buntansha) |
SEGAWA Yusaburo ISHINOMAKI SENSHU UNIVERSITY, フォトダイナミクス研究センター, チームリーダー (30087473)
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| Project Period (FY) |
1998 – 1999
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| Keywords | ZnO / MgZnO / Quantum Well / Photoluminescence / Exciton / Ultla-Violet Laser / Oxide |
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| Research Abstract |
High quality epitaxial layers of ZnO were successfully grown by laser MBE, which attracts much attention for new ultra-violet semiconductor lasers. For the fabrications of laser structures, development of cladding materials with larger bandgap than ZnO is important in this material system. Incorporation of Mg into ZnO up to 20% was successfully achieved using laser MBE, resulting in the increase of bandgap. Multi-quantum wells (MQWs) structures of ZnO/MgZnO were grown on sapphire substrates to observe the carrier confinement effects. The periodic structures with the order of lOnm in sizes were confirmed by a x-ray diffraction measurement as well as a transmission electron microscope observation. The minimum well width achieved in this study was about 1 nm. Low temperature photoluminescence(PL) and photoluminescence excitation(PLE) were performed to investigate the quantized electronic states in these structures. Blue shift of PL emission peaks as well as PLE absorption peaks were observed by decreasing the well width, which is in good agreement with the calculations based on quantum well structures. The large stokes shift between PL and PLE peaks exhibits that the localized excitons play an important role in these NIQWs, which was also confirmed from the result of temperature dependence of PL measurement.
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