报告题目：半导体胶体纳米材料的电荷转移和分离动力学（Charge Transport and Separation Dynamics in Colloidal Semiconductor Nano-materials）
报 告 人：陈缙泉 （华东师范大学）
报告时间：2017年4月27日（周四）10:00
报告地点：校本部G309
邀请人：金钻明
报告摘要：
In recent years, quantum confined semiconductor nanomaterials, such as quantum dots, nanorods and nanoplatelets, have received intense interest as light harvesting and charge separating materials for solar energy conversion. These novel materials offer many unique properties, including size-dependent absorption, large extinction coefficients over a broad spectral range, long exciton lifetimes, multiple exciton generation, enhanced photo-stability, and facile control of the spatial distribution of electrons and holes through composition and shape. In a typical photoreduction process, the conduction band (CB) electron in an excited light absorber is transferred to the electron acceptor (with a rate constant of kET) and the valence band (VB) hole to the (sacrificial) electron donor (kHT). These desirable forward processes compete with the electron-hole recombination both within the nanomaterials in the excitonic state and across the interface in charge separated states (kCR). We used femtosecond transient absorption technique to monitor these processes in colloidal semiconductor nano-materials and reveal the key factor for the photo-catalytic efficiency in quantum dots and nanorods-metal heterostructures.
