时间：2018年7月25日（周三）上午10：00 

地点：五号楼三楼会议室 

报告题目：Time-resolved study of III-V semiconductor nanowires.

报告人：Professor Arkady Yartsev, Lund University, Sweden

摘要：Semiconductor nanowires have many proven and promising applications. In collaboration with a strong scientific environment for nanowire production, Solid state Physics Division at Lund University, we have conducted a study of light-induced processes in several types of III-V nanowires. For most applications and from the fundamental point of view, understanding of the process of charge recombination is crucial. The other important characteristics of charges is their mobility. To study charge recombination in III-V nanowires and assess the dynamics of charge mobility, we apply a variety of time-resolved and steady state spectroscopy methods established at Chemical Physics, Lund University. We observed that for all nanowires studied, the non-radiative recombination of photo-generated charge carriers is the dominant process. Apparently, after photo-generation, charge carriers of one polarity (holes for most of nanowires studied) are trapped at the surface of the nanowires. This process is sensitive to the nanowire doping, composition, growth conditions, environment etc. The charges of other polarity (electrons) stay mobile before recombining via the non-radiative channel. The electron mobility is found to depend on the semiconductor composition decay with time.

报告人简介：Arkady Yartsev, Professor at Lund University, Sweden.Graduated at Moscow Institute of Physics and Technology in 1984 with specialization in physics and chemistry of fast processes. In 1984 joined Institute for Spectroscopy, Moscow, where studied elementary steps of photosynthesis, molecular dissociation, charge carrier dynamics in CdSe Quantum Dots and some other fast processes. In 1991 defended thesis in the subject of physics and mathematics on primary reaction steps in photosynthesis. During 1991 – 1993 had a postdoc position at the Institute for Molecular Sciences in Okazaki, Japan, with the main research topic of photo-induced intermolecular electron transfer and solvent/solute dynamics interactions. Early 1994 spent 4 month at Ume？ University, Sweden, studying ultra-fast barrierless photo-isomerization of cyanines in alcohol solutions. Later 1994,  joined newly found Division of Chemical Physics at Lund University, and worked there since. Among the main topics of research in Lund are light-induced processes in novel photovoltaic materials and on various interfaces as well as fundamental chemical photo-reactions in liquid phase.