Creation of Germanium Circular-polarized LED toward Optical Encrypted Communication

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02175
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Tokyo City University
• Principal Investigator: Sawano Kentarou 東京都市大学, 理工学部, 教授 (90409376)
• Co-Investigator(Kenkyū-buntansha): 徐 学俊 日本電信電話株式会社NTT物性科学基礎研究所, フロンティア機能物性研究部, 主任研究員 (80593334) ; 浜屋 宏平 大阪大学, 基礎工学研究科, 教授 (90401281)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: ゲルマニウム / LED / スピントロニクス / 円偏光

Outline of Final Research Achievements

Toward realization of Germanium circular-polarized LED for optical encrypted communication, Ge(111) high quality films were grown on Si(111) substrates. By means of wafer transfer technique, Ge-on-Insulator (GOI) substrates were fabricated. By depositing surface passivation films, we obtained large light emission enhancements. Mesa vertical type Ge(111) pin LEDs were fabricated by using in-situ doping, and very strong room temperature EL was successfully obtained. A single crystal high quality ferromagnetic films were grown as electrodes of the LED and the strong EL emission was obtained from the side edge, opening a route to realization of circular polarized light emission.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

本研究により完成した高効率Ge LEDの実現により、シリコンフォトニクス分野において、Si上の発光デバイスの集積化が可能となり、光配線実現へ向けて非常に大きな貢献となる。これにより、半導体チップの劇的な消費電力低減化が期待される。また、円偏光LEDが実現すれば、次世代の量子暗号技術や偏光多重通信、さらに分子認識技術、不揮発性光メモリなどの応用範囲が広がり、産業界に与える影響力が大きい。