Materials Research Center for Element Strategy, Tokyo Institute of Technology, Japan
摘要：Despite the demonstration of rapid improvement in record power conversion efficiency (PCE) over the past few years, the ultimate commercialization of organic–inorganic lead (Pb) halide perovskite solar cell technology is still facing serious challenges, most notably with regards to cell instability against moisture and temperature and the inclusion of toxic Pb. Therefore, it is important to fully understand the photovoltaic properties of all reported lead-free halide perovskites. In this seminar, I willintroduce the concept of electronic dimensionality to account for the photovoltaic properties of perovskite-based solar cell materials, with focus on the recently-proposed halide double perovskites. Our results explain the challenges for realizing promising Pb-free halide perovskite absorbers for thin-film solar cell applications. In addition, I will introduce the chemical origin of narrow band-gap beta-BaZn2As2, which is known as the parent phase of dilute magnetic semiconductor. The origins of this narrow band gap are discussed based on the chemical bonding nature probed by hard X-ray photoemission spectroscopy, hybrid density functional calculations and the ligand theory
简介：Zewen Xiao received his Ph.D. degree in Materials Science from Tokyo Institute of Technology in 2015 under the supervision of Prof. Toshio Kamiya and Prof. Hideo Hosono. He worked as a postdoctoral fellow in Prof. Yanfa Yan’s group at The University of Toledo (2015 to 2016). Currently, he is a Research Assistant Professor of Materials Research Center for Element Strategy in Tokyo Institute of Technology. He has published 30+ SCI papers, including 20 first-author papers published in journals including J. Am. Chem. Soc., Angew. Chem., Adv. Energy Mater., etc. His current research interest focuses on first-principles simulation and design of functional materials including photovoltaic absorbers, inorganic electrides and iron pnictides.
Selected Publications: 1. Zewen Xiao, et al., J. Am. Soc. Chem. 136, 14959-14965 (2014)
2. Zewen Xiao, et al., J. Am. Soc. Chem. 139, 6054-6057 (2017)
3. Zewen Xiao, et al., Angew. Chem. Int. Ed. Just Accepted, (2017)
4. Zewen Xiao, et al., Materials Horizon, 4, 206-216 (2017)