题 目: The ‘Birth’, ‘Death’ and ‘Life-Lengthening’ of Halide Perovskites
主讲人: Yuanyuan (Alvin) Zhou，Assistant Professor
主持人: 刘明侦 教授/青年千人计划
时 间 : 2018年7月11日（周三），9点30分
地 点 : 清水河校区研究院大楼304A
Yuanyuan (Alvin) Zhou is an Assistant Professor (Research) of Engineering since June 2016. He received his Ph.D. in Materials Science & Engineering (MSE) from Brown University in June 2016. He holds a B.S. in MSE from Xi’an Jiaotong University, and dual M.S. degrees in MSE from Xi’an Jiaotong University and Chemistry from Korea Research Institute of Chemical Technology. His research focuses on the fundamental materials-science topics of (opto)electronic and electrochemical ceramics (e.g. perovskites, halides, oxides, chalcogenides) for energy harvesting, storage and conversion. The topics include, but are not limited to, synthesis/processing, microscopic characterization, grain-boundary phenomena, nano-/quantum behaviors, and device engineering/mechanisms. Dr. Zhou has received several funding awards from US National Science Foundation (NSF), Office of Naval Research (ONR), Defense University Research Instrumentation Program (DURIP) and other agencies for his research. He has published 54 papers (41 papers as first/corresponding authors) in Chem, Joule, Nature Communications, JACS, Angewandte Chemie, Advanced Materials, Advanced Energy Materials, etc. with >2000 Google citations and 24 H-index.
Halide perovskites have recently emerged as a new family of semiconducting materials that are revolutionizing the field of photovoltaics. The rapid development of perovskite-based solar cells is being led by advances in microstructural/compositional engineering of perovskite thin films. In this context, understanding the ‘birth’ (crystallization) and ‘death’ (degradation), and developing new ways for the ‘life-lengthening’ (stabilization) of perovskites are becoming the most significant research directions.
In this talk, first, I will look at fundamental phenomena pertaining to nucleation & grain growth and grain-boundary evolution involved in the thin-film crystallization of perovskites from a materials-science perspective. Established scientific principles that govern these phenomena are invoked in the context of specific examples of perovskite thin films. Based on these fundamentals, our group have established a set of new synthetic strategies for scalable processing of high-performance large-area perovskite thin films and devices. Second, I will discuss the role of grain boundaries in the degradation processes of perovskites, and show our recent progress in the grain-boundary engineering of perovskite thin films for enhancing the perovskite stability. Finally, I will discuss the challenges and opportunities in the advanced characterization of perovskites for not only gaining a deep understanding of defects/microstructures, but also elucidating classical and non-classical phenomena pertaining to the crystallization, degradation, and stabilization of perovskites. The overall goal is to gain a deterministic control over the perovskite thin films with engineered microstructures/compositions for efficient PSCs that are also highly durable under environmental (heat/moisture/light) stresses.