Understanding Charge Carriers Transport and Recombination Pathways in TMD-based Heterojunctions Through Photoelectrochemical Microscopy

报告题目：Understanding Charge Carriers Transport and Recombination Pathways in TMD-based Heterojunctions Through Photoelectrochemical Microscopy

报告人：王力博士, 科罗拉多州立大学

时间：2020年01月14日16:00-17:00

地点：化学楼234会议室

报告摘要：

Van der Waals heterojunctions are attractive for solar energy conversion applications because light excitation produces carriers at charge-separating interfaces. The energy level offset at the interface drives charge separation on the femtosecond time scale. Current understanding of charge transport and recombination processes that follow the ultrafast charge separation step is mainly derived from solid-state device geometries where the TMDs are stacked on top of each other and electrical contacts are deposited on TMD edges. In this geometry, charge transport takes place parallel to the layers across micron-scale distances, thus resulting in the transport-limited device physics. Furthermore, these systems are not well-suited to represent real cases, especially in catalytical systems, where other factors as solid-liquid interfaces, surface defects/absorbates, dielectric environments could alter the carrier behavior. Based on a home-built photoelectrochemical microscopy system, we could tackle these problems through an efficient and high-throughput photocurrent mapping approach. At the same time, spatial-resolved, single-flake-level, structure-function relation based on 2D systems could be built.

报告人简介：

王力博士，2009年于武汉大学获得学士学位，同年保送至中国科学院大学长春应用化学研究所攻读博士学位，指导教师为卢云峰教授和耿延侯教授。博士期间，主要研究基于噻吩的有机半导体材料的合成及其在有机场效应晶体管和太阳能电池中的应用。2015年获得博士学位后，加入北达科他州立大学 (North Dakota State University) 孙文芳教授课题组，从事铱和铑化合物的合成及其非线性光学性能研究（主要研究其反饱和吸收性能）。2017年进入Houston Methodist Research Institute从事临床放射性药物的合成及质量检测，主要研究包括FDA认证C11及F18药物的合成。2018年加入科罗拉多州立大学（Colorado State University）转入研究二维材料的光电化学催化性能。以自主搭建测试平台为基础，探究二维 Mo(W)S(Se)2 的光电化学催化性能的时空各向异性，并进一步揭示了二维异质结中电荷分离后传输及复合机制。