2018 Fiscal Year Final Research Report
Elucidation of fundamental optical properties of biexcitons in deep ultraviolet ternary alloy quantum wells and application to laser operation
| Project/Area Number |
16H04335
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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 |
Electronic materials/Electric materials
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| Research Institution | Yamaguchi University |
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Principal Investigator |
Yamada Yoichi 山口大学, 大学院創成科学研究科, 教授 (00251033)
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| Co-Investigator(Kenkyū-buntansha) |
三宅 秀人 三重大学, 地域イノベーション学研究科, 教授 (70209881)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 励起子分子 / 励起子 / 励起子工学 / 混晶半導体 / 窒化物半導体 / 量子井戸 / 局在化 / 低次元化 |
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| Outline of Final Research Achievements |
We have evaluated the binding energy of biexcitons in AlGaN-based quantum wells with various structural parameters by means of photoluminescence excitation spectroscopy. We observed that the maximum value of the biexciton binding energy reached to 174 meV and confirmed that the normalized values of the confinement-enhanced biexciton binding energy were comparable to those for the GaAs-based quantum wells. We also observed that the photoluminescence due to many-body effects of excitons became dominant with increasing temperature from RT to 750 K owing to the delocalization of excitons and biexcitons with increasing temperature. Furthermore, we observed the deep-ultraviolet stimulated emission up to RT by means of optical pumping at low excitation power densities. We clarified that the formation of optical gain was excitonic in origin at least up to 200 K.
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| Free Research Field |
レーザ分光法による半導体光物性評価
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| Academic Significance and Societal Importance of the Research Achievements |
紫外から深紫外波長領域に基礎吸収端を有するAlGaN混晶半導体は、半導体材料の中でも最も大きな励起子効果を有することが期待されている。本研究では、AlGaN混晶量子井戸内に形成される励起子分子に着目し、その基礎物性を解明した。励起子分子は巨大結合エネルギーを有し、室温に留まらず、750Kの高温領域まで安定に存在することを明らかにした。これらの研究成果は、今後、励起子工学の観点からAlGaN混晶半導体を利用したデバイス設計、開発を進めていく上で、励起子系の輻射再結合過程を活用した高機能かつ高効率なデバイス作製の実現性を高めるものであり、その学術的意義は大きいものと考える。
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