2018 Fiscal Year Final Research Report

Application of InAs quantum dots with ultrafast carrier relaxation to terahertz wave detection devices

Research Project

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Project/Area Number	16K06266
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Electronic materials/Electric materials
Research Institution	National Institute of Advanced Industrial Science and Technology
Principal Investigator	Kumagai Naoto 国立研究開発法人産業技術総合研究所, エレクトロニクス・製造領域, 主任研究員 (40732152)
Co-Investigator(Kenkyū-buntansha)	北田貴弘徳島大学, 大学院社会産業理工学研究部(理工学域), 特任教授 (90283738) 盧翔孟徳島大学, 大学院社会産業理工学研究部(理工学域), 特任助教 (80708800) 南康夫徳島大学, 大学院社会産業理工学研究部(理工学域), 特任准教授 (60578368)
Project Period (FY)	2016-04-01 – 2019-03-31
Keywords	量子ドット / 光電流 / 光伝導アンテナ / テラヘルツ
Outline of Final Research Achievements	As an alternative to the case where it is not possible to carry out as planned, we made an characterization of lateral photocurrent in stacked InAs QDs layers for elucidating the photocurrent mechanism. Characterizing the temperature dependence of the photocurrent spectrum of InAs QDs layers with ultra-fast carrier relaxation embedded in strain-relaxed InGaAs, thermally continuous photocurrent around 1400 nm was observed in the range from low to room temperature. The photocurrent activation energy in the high temperature range over 169K was evaluated. The activation energy was dependent on its wavelength in the range of 1200-1600 nm of the peak of the photocurrent. The activation energy was 50-63 meV. And the longer the wavelength, the activation energy became larger. This result indicates that photocurrent activation energy corresponds thermal escape depth derived from size of QDs.
Free Research Field	電気・電子材料工学
Academic Significance and Societal Importance of the Research Achievements	「2次元電子系と0次元に閉じ込められた電子系が空間的に繋がった系」である自己組織化InAs量子ドットの面内光伝導という新しい切り口とその応用展開を図る上で、低温からの熱的に連続な光電流が確認でき、光電流の活性化エネルギーにドットの大きさが反映される事が示唆されたことにより、光電流メカニズムの一端を明らかにしただけでなく、光伝導アンテナの応用に向けて、低温でのアンテナ動作、ドットサイズによる光電流の活性化エネルギー制御について知見を得ることができた。