报告题目：Theoretical Design and Defect Understanding of Functional Materials
报告时间：2017年4月25 日 上午 9:00-10:00
摘要：Functional materials play important roles for many practical applications. However, most current functional materials have disadvantages more or less, thus requiring the finding of new materials with improved properties. At the same time, defects often dominate many properties of functional materials and a deeper understanding of defect properties would help the optimization of material performance. In this talk, I will present our recent works about theoretical design and defect understanding of functional materials. I will discuss the design of Si3AlP to improve Si solar cells and the design of lead-free halide perovskites to improve CH3NH3PbI3 solar cells using elemental transmutation methods based on known materials with known structures. I will also talk about the design of 2D SiS monolayers for energy conversion, optoelectronic, electronic, and thermoelectric applications using global structure search methods. Then I will present some of our recent new insights into defect properties of functional materials. Using CdTe as an example, I will discuss how to use annealing methods to overcome equilibrium Fermi level pinning, tune Fermi level positions precisely and reach high carrier concentration to realize the optimization of its photovoltaic performance. Then I will discuss defect-assisted non-radiative recombination process of carriers in CdTe and present our newly proposed mechanism beyond Shockley-Read-Hall theory. Finally, I will give a brief summary of these works.
个人简介：Dr. Ji-Hui Yang got his B.S. and Ph. D. in the Department of Physics at Fudan University in 2008 and 2013, respectively. After his graduation, Dr. Yang worked as Postdoc Researcher in the National Renewable Energy Laboratory, US, from 2012 to 2016. He currently works as a Postdoc Research Associate at Rice University. Dr. Yang’s research interests mainly focus on developing new theories and methods and using first-principles calculation methods to understand and design functional materials and devices for energy conversions, electronics and optoelectronics. So far, Dr. Yang has published more than 45 papers on leading scientific journals, 16 of which are first-author or corresponding-author papers, including Phys. Rev. Lett., J. Am. Chem. Soc., Nano Lett. Phys. Rev. B, Sci. Rep., J. Mater. Chem. A, J. Phys. Chem. C, et. al. His publications get a Google Scholar citation of more than 1900 times with an H index of 17.