Electrically pumped ZnO-based UV polariton laser operating at room temperature

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15453
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: Tohoku University
• Principal Investigator: Shima Kohei 東北大学, 多元物質科学研究所, 助教 (40805173)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 酸化亜鉛 / 分布ブラッグ反射鏡 / 微小共振器 / ヘリコン波励起プラズマ / 励起子ポラリトン / ポラリトンレーザ―

Outline of Final Research Achievements

To realize electrically pumped zinc oxide (ZnO) polariton lasers, chip-size planar ZnO microcavities (MCs) were fabricated by a top-down process. The ZnO MCs simultaneously maintained the high radiative performance of a ZnO active layer and high reflectivity of wide-bandwidth distributed Bragg reflectors (DBRs). Angle-resolved photoluminescence spectra of the ZnO MCs measured at different positions with a spot size of 80 um in diameter exhibited angle-dependent energy shifts in the near-band-edge emission, which arises from the emissions of lower polariton branch of the cavity-polaritons at room temperature. Furthermore, the current-voltage characteristics of p-n diodes fabricated within the ZnO MCs exhibited distinct rectification. The results are a significant milestone toward the realization of room-temperature ZnO-based polariton lasers.

Free Research Field

結晶工学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は(1)室温で共振器ポラリトンが存在可能なチップサイズ酸化亜鉛(ZnO)微小共振器の実現および(2)電流注入型ポラリトンレーザ構造の試作と整流特性の確認である。今後ポラリトンレーザ発振まで実現できれば「ポラリトンレーザは既存の半導体レーザと比較して省電力化に寄与するか」という学術的問いに答えられる。本デバイスはワイドギャップ半導体であるZnOの特徴を活かした近紫外線領域の省電力発光素子に応用できると考えられる。演色性に優れた自然な白色照明、高密度光情報記録素子、次世代量子情報通信素子への応用等、電子・環境・情報通信分野に貢献できる可能性があり、産業上のインパクトは計り知れない。