有机无机杂化钙钛矿单晶纳米结构的可控合成、光学性质及晶面效应研究

It has important scientific value and significance for optimizing application performance to investigate in detail the optical and electrical properties of organic-inorganic hybrid perovskite (OIHP). Based on the basic hybrid perovskite structure, we are going to take the microstructure as a medium to investigate in detail the effects of crystal face on the optical properties of OIHP, and reveal the native physical mechanism. The main contents are including: Synthesize the single-crystal nanorods, nanosheets and other nanostructures of OIHP and effectively control its morphology and advantages of crystal faces by varying the experimental parameters; Using advanced characterization techniques to explore the key factors for influencing the morphology and crystal face during crystal growth process and reveal the controllable mechanism of morphology and crystal face; Explore the relationship between morphology/crystal face and optical properties of band structure, defect states and photogenerated carries recombination and so on, thereafter establish and improve the control mechanisms of macroscopic optical properties; Study the decoherence, local equilibrium relaxation, relaxation cooling and isothermal complex dynamic process of single-crystal perovskite nanostructures, reveal the effects of morphology and crystal face on the kinetics of photogenerated carrier of OIHP and clarify the related physical mechanism. The relevant results will provide the experimental basis and theoretical reference for optimizing the application performance of OIHP photoelectric devices.

深入研究有机无机杂化钙钛矿材料的光电性质对于调控其应用性能具有重要的科学价值和意义。本课题从有机无机杂化钙钛矿基本结构出发，以调控微结构为媒介，旨在以晶面为切入点，深入研究晶面对钙钛矿单晶纳米结构光学性质的影响规律，并揭示其内在物理机制。具体内容包括：可控合成纳米棒、纳米片等钙钛矿单晶纳米结构材料，通过改变实验参数有效调控其形貌和优势晶面，利用先进表征技术探寻晶体生长过程中影响形貌和裸露晶面的关键因素，揭示形貌和晶面调控机制；探究形貌、晶面等要素与能带结构、缺陷态以及光生载流子复合等光学性能间的相互作用关系，建立和完善宏观光学性能调控机理；研究内部光生载流子退相干、局域平衡弛豫、弛豫冷却及等温复合等动力学过程，揭示形貌及晶面对有机无机杂化钙钛矿纳米结构单晶光生载流子动力学过程的影响规律，并阐明相关物理机制。该研究结果将为优化有机无机杂化钙钛矿光电器件的应用性能提供实验依据和理论参考。

钙钛矿材料是当前光电器件领域的明星材料，构建晶体结构、择优取向等结构因素与钙钛矿材料性能间的构效关系，对于指导提升其光电性能、推动其实际应用具有重要的科学价值和意义。本项目成功合成了一系列MAPbX3和CsPbX3量子点、纳米片及薄膜等材料，研究了反应条件、掺杂元素、添加剂等因素对晶体结构、择优取向、发光性能和光伏性能的影响。取得成果有：利用添加剂CTAB在常温下诱导MAPbBr3由量子点转变为纳米片；利用TDM诱导钙钛矿纳米晶择优生长取向由(002)晶向转变为(022)晶向，提高了发光量子产率；通过引入CTAB获得了高荧光效率、高稳定性的富溴CsPbBr3纳米晶；采用高温热注入法制得CsPbI3纳米线，变温PL结果表明电子-声子耦合作用使得发光峰位随温度增加而持续性蓝移；开发了一种酒石酸添加剂工程与超声波处理相结合的方法，实现了铅锡二元钙钛矿薄膜（224）晶面的择优取向生长，其太阳电池的最高光电转换效率（PCE）达到15.59％；成功制备了Cu-Pb二元钙钛矿薄膜，发现掺杂适量的Cu后，其晶体结构由原本的扭曲四方晶体结构向立方晶体结构转变，几何对称性明显改善，晶粒尺寸增大至~2μm，光致发光强度较MAPbI3薄膜增强6倍；将多功能分子4TA作为添加剂调节钙钛矿薄膜结晶质量，获得大晶粒，提高稳定性，将太阳电池的PCE提高到20.24%。上述成果为优化钙钛矿光电器件的应用性能提供了实验依据和理论支持，也从晶体结构调控角度为提高钙钛矿太阳电池光伏性能提供了有效的技术方案。上述成果在AFM,CEJ,Nano Energy,Nano Research等国际期刊上发表相关的SCI论文18篇，其中中科院1区SCI论文16篇，且包含国内1区SCI论文3篇，授权国家发明专利2项，获吉林省自然科学二等奖1项；培养本研究领域的博士毕业生2名，硕士毕业生5名。