有机无机杂化钙钛矿晶体中组分间相互作用及其光电特性的可控研究

Organic-inorganic hybrid perovskites, where the both components are assembled in a molecular level within crystalline structure, have a variety of compositional combinations. Recently, this family of materials has received intensive attention in academia, due to its rapidly increasing power conversion efficiency (PCE) in photovoltaic applications. Combining with low cost, ease of fabrication and outstanding properties, this materials has been widely explored as optoelectronics, such as LED, photodiodes, lasers, as well as solar cells. .With further understanding in its chemical and physical properties, it gives birth to novel device design to fully utilize the advantages that perovskites have already known. Meanwhile, novel materials design has been expected to meet the requirements in applications where perovskite based devices are used in certain conditions. So far, research efforts have been mainly addressed in either fundamental understanding or practical use, respectively. It is emergent to find the underlying mechanism that bridge its chemical composition/crystal structure to its optoelectronic properties for further application purpose. .This proposal mainly focuses on the interactions between organic/inorganic components in hybrids perovskite materials. The interactions affect materials crystal structure, and physical/chemical properties including, major optoelectronic properties, thermal/chemical stability, and etc. These interactions can be carefully controlled by rationale design of organic components with desired functional groups that bond to the inorganic components through physical neighboring, chemical bonding or energy transfer, which further influence the device performance. The outcome of the efforts addresses various critical issues from fundamentals, including film growth and stability, which will provide sufficient evidence and experimental data to support theoretical design and eventually pave the way for the practical use of hybrids perovskite as next generation of optoelectronics.

有机无机杂化钙钛矿材料由有机无机组分通过分子尺度的静电力相互作用形成长程有序晶体结构（微米以上尺度）。其组分选择丰富、结构多样、物化性质各异。目前，钙钛矿材料已经被成功地应用于太阳能电池。随着人们对其优异的光电性能的研究深入，基于钙钛矿材料的其它光电器件也相继被报道如发光二极管、光探测器以及激光器。然而由于组分的多样性，对杂化钙钛矿材料的设计研究与进一步器件开发仍然停留在试错实验阶段。人们缺乏对材料的组成构型与理化性质的构效关系的理性认识。.本项目拟从钙钛矿晶体中有机和无机组分间的相互作用着手，研究各组分相互作用及其对材料光电性能的影响；通过有针对性的引入有机物种，控制其与无机物种的相互作用，改变体系晶体结构及电子排布，从而实现对材料理化性质的控制。该研究将建立钙钛矿光电性能调控原则，为钙钛矿材料的性能可控设计提供理论指导和实验数据，从而服务于高效能、低成本的光电器件的开发和应用。

近年来，基于有机无机杂化钙钛矿材料的光电器件取得了长足发展。这类晶体中ABX位的有机无机组分通过静电力作用以分子形式形成长程有序晶体结构，其组成丰富，结构多样，物化性质各异。作为一类新型光电半导体材料，研究组成构型与最终性能相关联，对提升材料和器件性能，拓展其应用空间有重要价值。本项目研究钙钛矿晶体中有机和无机组分间的相互作用，通过相互作用调控，实现材料光电性的理性调控。.重要的研究成果包括：1）基于有机无机杂化钙钛矿中有机阳离子空间位阻效应构筑二维晶体，由此构筑准二维太阳能电池，效率达到13%；2）引入多螯合位点制备复杂纳米晶体结构，由此制备宽谱发光的低维类钙钛矿单晶，内量子效率达到12%；3）引入偶极分子调控有机无机杂化钙钛矿光电性能，器件认证效率突破23%；4）新型有机无机杂化钙钛矿器件稳定性提升，封装后器件稳态工作1000小时衰减小于20%。相关研究成果发表发表SCI论文24篇，代表性论文包括Nat Commun 两篇，Angewandte Chemie International Edition 两篇，Adv Mater 两篇，ACS Nano 一篇，Energy & Environmental Science一篇等。研究得到了广泛关注，其中3篇论文先后入选ESI高被引论文。研究为建立钙钛矿光电性能调控原则进行了有益的探索，为发展高效稳定的钙钛矿光电器件提供理论指导和实验支撑。