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关于中国科学院深圳先进技术研究院、中组部海外高层次人才李江宇教授学术报告会的通知

时间:2019-12-05 11:47      发布人:何秋云      阅读:90

报告题目:Correlating Polar Order, Ionic Migration, and Photocurrent in Organometallic Halide Perovskites

报 告 人:李江宇(中国科学院深圳先进技术研究院)

邀 请 人:曹镛  院士

报告时间:2019年12月16日(周一)上午10:00-11:30

报告地点:北区科技园1号楼发光材料与器件国家重点实验室502室

 

摘要:

Organometallic halide perovskite solar cell has emerged as one of the most exciting photovoltaic technologies in the last a few years, though many fundamental questions remain unanswered. In an attempt to resolving the intrinsic lattice structure of CH3NH3PbI3 by transmission electron microscopy, we identified a general decomposition pathway from CH3NH3PbI3 to PbI2 through an intermediate superstructure of CH3NH3PbI2.5, which appears to hold for CH3NH3PbBr3 and CsPbI3 as well. Importantly, the decomposition barrier is orientation-dependent, and the degradation can be slowed down substantially by carbon coating, enabling us to design a new perovskite solar cell with improved stability and reduced hysteresis. Detailed microscopy analysis reveals that the superstructure diffraction corresponds to ordered vacancies or vacancy-interstitial pairs of I, and interestingly, this Frenkel pair can be induced by electric field and stabilized in PVDF matrix, resulting in anomalously enhanced remnant polarization and electromechanical coupling in the nanocomposite that is also highly stable. Nevertheless, the intrinsic instability prevented us to acquire the atomic image of CH3NH3PbI3, and we have to resort to scanning probe to distinguish the fine structure difference between two competing space groups, revealing alternating polar and nonpolar orders in CH3NH3PbI3 and their effects on photocurrent. This presentation thus summarizes close collaborations in the last two years among Shenzhen Institutes of Advanced Technology, Peking University, Shijiazhuang Tiedao University, and Beihang University, among others, and we are continuing to explore the defect structures in halide perovskites and their far reaching implications.

 

报告人李江宇简介:1972年5月出生,1994年毕业于清华大学材料科学与工程系,在美国科罗拉多大学获机械工程硕士(1996年)、电子工程硕士学位(1998年)及机械工程博士学位(1998年8月),曾在加州大学圣地亚哥分校、加州理工学院从事博士后研究。2001年8月被聘为内布拉斯加大学林肯分校助理教授。2006年加入美国华盛顿大学机械工程学院,任教授和主管科研的副系主任。2019年加入中国科学院深圳先进技术研究院教授、国家“****”专家、深圳市“孔雀计划”A类人才,教育部“新世纪优秀人才支持计划”入选者。

 

李江宇教授长期致力于多功能智能材料与结构力学行为研究,曾主持美国自然科学基金项目、美国陆军研究项目和美国化学学会石油研究基金项目,共发表SCI论文200余篇,包括Science、Nature Materials、PNAS、PRL等国际顶级期刊,被引用8800余次;研究成果获Nature、Science等顶级期刊亮点显示,美国物理学会、材料研究会和英国皇家化学学会等专业组织专题报道,以及美国NBC、英国BBC和英国New Scientist杂志等传媒特约专访;曾获美国机械工程师协会SiaNemat-Nasser奖章、Microscopy Today Innovation Award from Microscopy Society of America、ICCES青年成就奖等荣誉。任美国物理联合会Journal of Applied Physics副主编、自然出版集团npj Computational Materials、Mechanics of Materials编委、中国硅酸盐学会Journal of Materiomics编委、中国力学学会Theoreticaland Applied Mechanics Letters编委。