Examination of the possibility of realizing light-emitting devices based on excitonic effect using nitride semiconductors.

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04585
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Tokuyama College of Technology
• Principal Investigator: Murotani Hideaki 徳山工業高等専門学校, 情報電子工学科, 教授 (20612906)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 窒化物半導体 / 励起子 / 誘導放出 / レーザー発振 / 内部量子効率

Outline of Final Research Achievements

In this study, in order to examine the possibility of realizing light-emitting devices based on the excitonic effect in nitride semiconductor quantum well (QWs), excitonic optical properties were evaluated. We have evaluated the temperature and excitation power density dependence of the internal quantum efficiency (IQE) in AlGaN-based QWs. It was found that the obtained excitation density dependence of the IQE can be described by a rate equation model based on the exciton recombination process. This indicates that the optical transition process of excitons is involved in the luminescence mechanism in AlGaN-based quantum well structures. Furthermore, it was shown that stimulated emission involving the optical transition process of excitons occurs in AlGaN-based QWs even at room temperature, and optically pumped lasing due excitonic optical gain formation process was observed at room temperature.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

半導体においてキャリア（電子と正孔）が励起されると，電子と正孔はクーロン相互作用によって互いに束縛された励起子状態となる。励起子の発光過程や励起子多体効果に基づく光学遷移過程は，高い遷移確率を有していることや、光学利得の生成が期待できるため、この過程を利用することで発光デバイスの性能向上が見込まれる。室温においても励起子が安定に存在し得る半導体材料として、窒化物系半導体があげられる。窒化物半導体は赤外線領域から深紫外線領域で発光可能な材料であり、窒化物半導体によって励起子効果を利用した発光デバイスを実現することで、発光デバイスの性能を著しく向上させることができると期待される。