Dynamics of excitonic properties in water-soluble CIS semiconductor quantum dots

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K04938
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied materials
• Research Institution: Nippon Bunri University
• Principal Investigator: ICHIDA HIDEKI 日本文理大学, 工学部, 特任准教授 (50379129)
• Co-Investigator(Kenkyū-buntansha): 金 大貴 大阪市立大学, 大学院工学研究科, 教授 (00295685)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 半導体ナノ粒子 / 分光計測 / 発光ダイナミクス

Outline of Final Research Achievements

In this work, we have investigated that the sample preparation and excited state dynamics in I-III-VI quantum dots (QDs) such as CuInS2 QDs, which has attracted attention as a new materials substance with high quantum efficiency comparable to that of cadmium-based nanoparticles.　Water-soluble CuInS2 QDs were hydrothermally prepared in the presence of N-acetyl-L-cysteine as a stabilizer, and the optimal hydrothermal synthetic conditions for NAC-capped CIS QDs were investigated. The photoluminescence quantum yield (QY) of the CIS QDs synthesized under optimal conditions was 4%, which was comparable with the highest QY reported for water-soluble CIS core QDs. The introduction of a ZnS shell produced CIS/ZnS core/shell QDs and further increased the PL QY to 30%. In order to clarify the PL origin, PL-decay profiles and time-resolved PL spectra were measured. From the experimental results, we have found that the PL origin is donor-acceptor pair luminescence.

Free Research Field

光物性

Academic Significance and Societal Importance of the Research Achievements

半導体ナノ粒子は，量子サイズ効果によってバルク結晶とは異なる光学特性を示すことから，新しい光機能性材料として注目されており，その中でもカドミウムフリーの新材料として，I-III-VI 族半導体ナノ粒子が着目されている，本研究は，このI-III-VI 族半導体ナノ粒子の中のCuInS2ナノ粒子において，非常に高い量子効率を有する試料の作製に成功し，その光学特性を明らかにし，新しい光機能性材料への応用に向けた知見を得た．