SEMINAR
The State Key Lab of
High Performance Ceramics and Superfine Microstructure
Shanghai Institute of Ceramics, Chinese Academy of Sciences
中 国 科 学 院 上 海 硅 酸 盐 研 究 所 高 性 能 陶 瓷 和 超 微 结 构 国 家 重 点 实 验 室
2016年度国家重点实验室特邀学术报告

Photo-induced Ferroelectric Switching in Perovskite CH3NH3PbI3 Films

赵晋津

中科院深圳先进技术研究院

时间：2016年12月19日（星期一）下午2:00

地点： 2号楼607会议室（国家重点实验室）

欢迎广大科研人员和研究生参与讨论！

联系人：陈航榕（5305）

　　报告摘要：

　　The photovoltaic conversion efficiency of perovskite solar cells based on organic-inorganic CH₃NH₃PbI₃ has risen spectacularly from 3.8% to over 22% in just seven years, yet quite a few important fundamental issues have not been settled, and the role of spontaneous polarization remains poorly understood. While piezoresponse force microscopy (PFM) has been adopted to probe possible ferroelectricity in CH₃NH₃PbI₃, the reported data are often conflicting and inconclusive, due to complexity in apparent piezoresponse and its switching that may arise from ionic motions, electrostatic interactions, and other electromechanical mechanisms. Herein, using a combination of microscopic and macroscopic measurements, we unambiguously establish the linear piezoelectricity of CH₃NH₃PbI₃ arising from its spontaneous polarization, which can be switched by an electric field, though other electromechanical contributions, such as ionic motions are also shown to exist. More importantly, we demonstrate strong interactions between polarization and light in technologically relevant CH₃NH₃PbI₃ films with good conversion efficiencies, observing that the spontaneous polarization can also be switched by light illumination in the absence of electric field, and the photo-induced surface charges and potentials are shifted by the spontaneous polarization. This set of studies offer strong evidence on the interactions among photo-induced charges, polarization, and possibly ions in perovskite CH₃NH₃PbI₃, and these fundamental observations lay the ground for answering the technologically important question regarding the effects of ferroelectricity on its photovoltaic conversion. 

　　报告人简介：

　　赵晋津，博士，副教授，中科院深圳先进技术研究院客座研究员。2005.9-2010.7 中国科学院上海硅酸盐研究所，硕博连读获工学博士学位；2010.8至今在石家庄铁道大学工作。2007.10-2008.10 在德国马普学会胶体与界面研究所联合培养；2015.8-2016.8 在美国华盛顿大学（西雅图校区）访问学者。目前主要从事于钙钛矿结构有机金属卤化物光电晶体和薄膜器件制备及其光电热耦合机理研究。近五年发表SCI论文30余篇，已授权国家发明专利9项，主持国家自然科学基金、国家重点基础研究发展计划（973计划）前期专项子课题、河北省自然科学基金优秀青年项目、河北省青年拔尖人才项目等12项。河北省电动汽车产业协会顾问专家，河北省教育厅“三三三人才工程”第三层次专家人选专家。