物理与电子工程学院2019学术论坛之四
报告题目：Resolving the Role of Polarization and Ionic Migration in Single Crystal Organometal Halide Perovskite
报告人：赵晋津教授（石家庄铁道大学）
时间：2019年4月10日，下午:13:40~14:40
地点：理学实验楼409
摘要 Nano/micro-scale perovskites composition of organometal halide have been reported to possess excellent photovoltaic efficiency with minimal hysteresis, and in this work, we shade nanoscale insight into the roles of illumination-induced ferroelectric polarization and ionic migration in photovoltaic hysteresis. By examining concurrent evolution of ionic migration and spontaneous polarization of nano/micro-scale single crystal perovskite under light illumination using dynamic strain based scanning probe microscopy, we observe strong linear piezoelectricity arising from photo-enhanced polarization, while ionic migration is found to be not significantly increased by lightening. Nanoscale photocurrents are mapped under a series of biases using conductive atomic force microscopy, revealing negligible difference between forward and backward scans, and local IV curves reconstructed from principal component analysis show minimal hysteresis of just 1%. These observations at nanoscale are confirmed in macroscopic perovskite solar cell, exhibiting high efficiency of 20.11% with hysteresis index as small as 3%. We thus directly correlate ionic migration, ferroelectric polarization, and photocurrent hysteresis at the nanoscale, and establish photo-enhanced polarization in triple-cation mixed-halide perovskite, which does not contribute to the photovoltaic hysteresis.
报告人简历：赵晋津，女，1982年出生，博士，石家庄铁道大学教授，九三学社石家庄铁道大学支社副主委。2010年博士毕业于中国科学院上海硅酸盐研究所，2007年和2015年分别在德国马普学会胶体与界面研究所，美国华盛顿大学访学研究，在Nature Communications，Nano Energy等期刊上发表论文40 余篇，总引用1140余次，h-index为17；申请国家发明专利28项，已授权国家发明专利14 项；主持国家重点基础研究发展计划（973 计划）前期专项子课题、国家自然科学基金（青年、面上）、河北省自然科学基金优秀青年项目等15 项。被授予河北省 “三三三人才工程”专家，“河北省优秀硕士毕业论文指导教师”，“河北省青年拔尖人才”等称号， 获得2018中国新锐科技卓越影响奖。
