报告时间： 2012年9月20日（星期四）上午10:00
报告地点：玉泉校区教4-404
报告题目：Defects in earth-abundant solar cell materials: A first-principles perspective
报告人：Prof. Shengbai Zhang
(Professor in Physics
Department of Physics, Applied Physics, and Astronomy
Rensselaer Polytechnic Institute)
联系人：王勇教授 (yongwang@zju.edu.cn)
欢迎大家参与，现场刷卡签到。
报告摘要：
In this talk, first-principles theory used to guide the development of better earth-abundant solar cell materials will be introduced. It will be composed of two parts. The first part is the discussion of the defect properties of Cu2ZnSnS4 (CZTS), a hallmark earth-abundant solar-cell material. The defects substitutional Cu clusters on the Sn sites were identified as the main source of deep traps. The other part is the discussion of elimination of carrier traps at edge dislocations by passivation. It was found that passivation efficiency follows the Fermi-Dirac distribution in which the allowed amount of dopants in bulk serves as the effective Fermi energy. Application to silicon reveals that acceptors are generally more effective in passivating edge states than donors.
报告人简介：
Dr. Zhang received his Ph. D. in Physics from the University of California at Berkeley in 1989, under the supervision of Professor Marvin L. Cohen. Dr. Zhang then joined Xerox PARC in Palo Alto, California, where he performed postdoctoral research with Dr. Jim Chadi and Dr. John Northrup. In 1991, he moved to the National Renewable Energy Laboratory (NREL) in Golden, Colorado and became group leader for Computational Materials Science in 2005. In 2008, he was appointed Senior Kodosky Constellation Chair at Rensselaer Polytechnic Institute in Troy, NY.
Dr. Zhang has a broad theoretical research background in computational materials physics, which covers a range of inorganic and organic semiconductors and solids for bulk properties, defect structures, and surface physics. His most recent work involves earth-abundant photovoltaic materials, phase change memory materials, van der Waals interaction in organic semiconductors, lithium battery materials, hydrogen storage, topological insulators, graphene, and excited state dynamics. Dr. Zhang has more than 250 peer-reviewed publications with 8,700 citations (H index = 50). He has been a Fellow of the American Physical Society since 2001.
主办：云顶yd222线路检测材料科学与工程学系
宣传：云顶yd222线路检测材料系研究生会、博士生会
