Misaka Tomoki, Ohoyama Hiroshi, Matsumoto Takuya
Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, Japan.
Sci Rep. 2022 Oct 6;12(1):16678. doi: 10.1038/s41598-022-21111-9.
Plasmon-induced charge separation (PICS) is an efficient way to use the hot carriers generated by localized surface plasmon resonance. Although the ultrafast dynamics of hot carrier generation and annihilation itself are well understood, the slow dynamics of PICS are not, despite their importance for the use of hot carriers in chemical reactions. In this work, we directly observed the slow dynamics of PICS on an Au nanoparticle (NP)/TiO interface by using electrostatic force microscopy with time-resolved measurements obtained by sideband signal of frequency shift. The change in contact potential difference induced by PICS had a bias voltage dependence, indicating that the number of holes in the Au NPs ([Formula: see text]) accumulated by laser irradiation depended on bias voltage. The decay constant for the annihilation of the separated charge on the Au NPs at the Au NP/TiO interface was directly determined to be ca. 150 ms, and the annihilation process was discussed in a simple model based on the transient Schottky barrier.
等离子体激元诱导电荷分离（PICS）是利用局域表面等离子体共振产生的热载流子的一种有效方式。尽管热载流子产生和湮灭的超快动力学本身已被充分理解，但PICS的慢动力学却并非如此，尽管它们对于在化学反应中使用热载流子很重要。在这项工作中，我们通过使用静电力显微镜并利用频移边带信号获得的时间分辨测量，直接观察了金纳米颗粒（NP）/TiO界面上PICS的慢动力学。PICS引起的接触电势差变化具有偏置电压依赖性，这表明激光照射积累在金纳米颗粒（[公式：见原文]）中的空穴数量取决于偏置电压。直接确定金纳米颗粒/ TiO界面上金纳米颗粒上分离电荷湮灭的衰减常数约为150毫秒，并在基于瞬态肖特基势垒的简单模型中讨论了湮灭过程。
