Creation of ultrawide-bandgap-semiconductor exciton-engineering using deep-ultraviolet time and spatially resolved spectroscopies under extreme environments

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02615
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: Kyoto University
• Principal Investigator: Ishii Ryota 京都大学, 工学研究科, 助教 (60737047)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: フォトルミネッセンス / エレクトロルミネッセンス / 窒化物半導体 / ダイヤモンド / 励起子 / 深紫外分光 / 近接場分光 / 極限環境下分光

Outline of Final Research Achievements

This study explored the excitonic properties of ultrawide bandgap semiconductors and the techniques of deep-ultraviolet time and spatially resolved spectroscopies under extreme environments. These include, unveiling that threading dislocations act as non-radiative recombination centers in blue-emitting LEDs at above room temperatures, first observation of deep-ultraviolet band-edge emission from nano-polycrystalline diamond, elucidating the internal quantum efficiency, current injection efficiency, and light extraction efficiency of AlGaN-based deep-ultraviolet LEDs, demonstration of deep-ultraviolet scanning near-field optical microscope with spatial resolution better than 100 nm, resolving the bound excitonic properties of n-type aluminum nitride.

Free Research Field

半導体光物性

Academic Significance and Societal Importance of the Research Achievements

波長200 nmから300 nmの深紫外光は，浄水やウイルスの不活化，ラベルフリー生体イメージング，および半導体微細加工技術などに大変有用である．超ワイドギャップ半導体は深紫外光源の1つとして注目されているが，現状超ワイドギャップ半導体を用いた深紫外光源の性能は低く留まっている．そこで本研究では，未だ成熟していない深紫外分光の深化とともに，深紫外分光を用いた超ワイドギャップ半導体の光物性解明に取り組み，深紫外光源の高性能化に繋がる超ワイドギャップ半導体の基礎光物性を明らかにすることに成功した．