| Project/Area Number |
16K06264
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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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 |
Kurai Satoshi 山口大学, 大学院創成科学研究科, 助教 (80304492)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 顕微分光 / InGaN / 量子井戸構造 / ポテンシャル障壁 / 貫通転位 / 空間分解分光 / 窒化インジウムガリウム / 近接場光学顕微分光 / GaInN |
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| Outline of Final Research Achievements |
Spatial distribution of local high-energy emissions, which were observed at surface pits originating from threading dislocations in InGaN quantum well (QW) structures fabricated on c-plane sapphire substrates, was evaluated by scanning near-field optical microscopy (SNOM). Low temperature SNOM measurements revealed positional correlation between dark contrast and high-energy emission in blue and green QWs, that is direct observation of self-formation of energy barriers (200 to 300 meV in height) at dislocations. In addition, local high-energy emissions were also observed at threading dislocations in the AlGaN QW structures by cathodoluminescence method. In this case, no surface structure such as surface pits was observed, suggesting the different mechanism from that in the InGaN system.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究では、下地構造の異なる青色QW、青色に比べ効率の低い緑色QWおよび深紫外AlGaN QWにおいて貫通転位近傍に自己形成される特異なエネルギー障壁の観察および障壁高さの定量評価を行った。貫通転位近傍にエネルギー障壁が形成され、キャリアが欠陥において非発光となるのを抑制することが青色LEDの高効率化に有用とされており、観測された発光エネルギーの空間分布がデバイスの発光効率改善に繋がる可能性を示した。
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