| Project/Area Number |
18K19028
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 30:Applied physics and engineering and related fields
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| Research Institution | Tohoku University |
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Principal Investigator |
Kojima Kazunobu 東北大学, 多元物質科学研究所, 准教授 (30534250)
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| Co-Investigator(Kenkyū-buntansha) |
谷川 智之 大阪大学, 工学研究科, 准教授 (90633537)
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| Project Period (FY) |
2018-06-29 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2018: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000)
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| Keywords | 窒化ガリウム / 全方位フォトルミネセンス / 多光子顕微鏡 / 点欠陥 / 貫通転位 |
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| Outline of Final Research Achievements |
An optical measurement system based on an integrating sphere was built up to perform the omnidirectional photoluminescence (ODPL) spectroscopy under the multiple-photon absorption (MPA) condition. The detection sensitivity of the system was verified to be enough high by the quantification of quantum efficiency of radiation in a GaN crystal. Photoluminescence (PL) spectra and PL decay lifetime were realized to be drastically changed when the excitation depth was varied. Such the sensitive variation of PL spectra and lifetimes arises from the self-absorption and surface recombination processes of the crystal.
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| Academic Significance and Societal Importance of the Research Achievements |
近年成長技術の発展が著しいGaN自立結晶の、さらなる高品質化に寄与するものと考えられる。特に、貫通転位密度が非常に低いGaN基板を用いてもなお、デバイス性能のばらつきなどが多数報告されている。本手法を用いて点欠陥濃度の分布が明らかとなれば、このような歩留まりの問題に対して有効なアプローチを講じることができると期待できる。また、無機・有機を問わず、他の直接遷移型半導体における光物性評価においても有用な分光技術になるものと期待する。
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