报告题目：From Lead Halide Perovskites to Lead-Free Metal Halide Perovskites and Double Perovskites: Insights from Density-Functional Theory

报告人：Yanfa Yan (Professor, Department of Physics and Astronomy, and Wright Center for Photovoltaic Innovation and Commercialization, The University of Toledo, United States)

报告时间为2018年5月28日(星期二) 上午10:00

报告地点在中国科学院半导体研究所图书馆101会议室

摘要：Despite the demonstration of rapid improvement in record power conversion efficiency over the past few years, the ultimate commercialization of organic–inorganic lead (Pb) halide perovskite (ABX3) solar cell technology, where A is a relatively large inorganic or organic cation (e.g., Cs+, CH3NH3+), B = Pb and X = Cl, Br, I, is still facing serious challenges, most notably with regards to cell instability against moisture and temperature and the inclusion of toxic Pb. Extensive efforts have been paid to discover nontoxic or low-toxicity and air-stable metal halide perovskite-based solar cell materials. Substituting Pb by another divalent cation to form Pb-free perovskites or a combination of monovalent (BI) and trivalent (BIII) cations to form A2BIBIIIX6 halide double-B-cation perovskites has been considered one attractive approach for achieving this goal. In this talk, we review the effects of Pb substitution through density functional theory calculations, focusing on three critical issues: optical absorption; defect properties; and stability. Our results explain the challenges for realizing promising Pb-free halide absorbers for thin–film solar cell application via Pb substitution.

报告人简介：Yanfa Yan is a Professor and the Ohio Research Scholar Endowed for Photovoltaics Innovation and Commercialization in the Department of Physics and Astronomy at the University of Toledo (UT). He earned MS and Ph D in Physics from Wuhan University. Previously, he was a Principal Scientist at the National Renewable Energy Laboratory (NREL), USA. His expertise includes (1) Theory of defect physics and electronic properties in semiconductors; (2) Materials synthesis and thin film solar cell fabrication; and Nanoscale characterization of thin film solar cell materials. His current research efforts include developing processes to fabricate high efficiency thin-film solar cells (CdTe and perovskite) and designing and validating new absorber materials for thin-film solar cell applications. He has received DOE/EERE Young Investigator and R&D 100 awards. He is a Fellow of the American Physical Society.