Hotcarrier and Multicarrier Transfer Dynamics and Charged Excitons in Semiconductor Nanocrystal Hybrid Systems

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03773
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Kwansei Gakuin University
• Principal Investigator: TAMAI Naoto 関西学院大学, 理工学部, 教授 (60163664)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 半導体ナノ微粒子 / 荷電励起子 / ホットキャリア / マルチキャリア / 過渡吸収分光

Outline of Final Research Achievements

For understanding the quantum confinement effects on hot carrier transfer, we synthesized several kinds of semiconductor quantum dots (QDs) and nanoplatelets (NPLs) by a colloidal synthetic method, and Au and Pt metal nanoparticles (NPs) were attached on the surface of semiconductor nanocrystals. We found that hot carrier transfer takes place from 1P(e) state in Au-CdSe QDs, whereas no hot carrier transfer was detected in Au and Pt-CdSe NPLs even though the ultrafast carrier transfer faster than the instrument response function (~ 60 fs) exists in Pt-CdSe NPLs. This difference between QDs and NPLs can be interpreted in terms of very efficient and ultrafast phonon emission from higher excited states of CdSe NPLs and phonon bottle neck in CdSe QDs. Charged excitons in CdSe QDs and NPLs were also examined by photochemical electron doping to QDs and NPLs.

Free Research Field

光物理化学