Study on Dynamics of Plasmon-Induced Charge Carriers under the Modal Strong Coupling Conditions

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15113
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28020:Nanostructural physics-related
• Research Institution: Hokkaido University
• Principal Investigator: Shi Xu 北海道大学, 創成研究機構, 准教授 (20749113)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: transient spectroscopy / strong coupling / electron dynamics / plasmon / cavity

Outline of Final Research Achievements

In this study, I focused on the dynamics of plasmon-induced electron under the strong coupling conditions. By constructing a Au-NPs/TiO2/Au-film structure with Au-NPs fully inlaid inside the TiO2, the strong coupling between the plasmon resonance of Au-NPs and the cavity resonance is verified to be strongly determined by the electric field in the cavity. Using this coupling strength tunable nanostructures, we studied the electron transfer from Au-NPs to TiO2 as well as the electron-electron, electron-phonon coupling of Au-NPs using transient spectroscopy with a reflection configuration. We found that under the strong coupling conditions, a higher photo-induced electron transfer was observed. In addition, based on the study of electron-electron coupling and electron-phonon coupling of Au-NPs, we found that the electron-electron coupling and/or electron-phonon coupling of Au-NPs were modified under the strong coupling conditions.

Free Research Field

photochemistry

Academic Significance and Societal Importance of the Research Achievements

Understanding of the enhanced photochemical reactions in the modal strong coupling system by exploring the dynamics of the plasmon-induced electron transfer and the electron-electron, electron-phonon coupling will be beneficial for the future development of plasmonic solar energy conversion system.