基于同步辐射X射线散射技术的钙钛矿半导体结晶原位研究

In-Situ Investigation of Perovskite Crystallization Based on Synchrotron Radiation X-ray Scattering

有机-无机杂化钙钛矿具有带隙连续可调、可低成本溶液加工、电荷传输性能优异等优点,其太阳电池光电转化效率在短短十年间已经超过25%。然而,目前人们对高品质钙钛矿薄膜制备过程中的结晶行为认识不足,高质量晶体可控制备存在巨大挑战,阻碍了钙钛矿光伏的产业化发展。基于同步辐射X射线散射技术,作者团队系统地研究了三维有机-无机杂化钙钛矿MAPbI_(3)和FAPbI_(3)、二维有机-无机杂化钙钛矿Ruddlesden-Popper(RP)型(BA)_(2)(MA)_(3)Pb_(4)I_(13)和层间阳离子交替(ACI)型(GA)(MA)_(3)Pb_(3)I_(10)、以及全无机钙钛矿CsPbI_(2)Br5种体系的成膜结晶动力学过程,揭示了钙钛矿结晶原位生长过程的相变机制和各种相的演变动力学,对相应的观测方法、研究成果进行了总结评述,希望促进钙钛矿结晶动力学机制方面的原创性研究,推动钙钛矿光电技术的发展。

Hybrid organic-inorganic halide perovskites have attracted paramount interest due to their adjustable band gap,solution processibility for solar cells and excellent optoelectronic properties,and its solar cells power conversion efficiencies have reached higher than 25%.In this brief review,we provide a brief overview of phase transformation and conversion for different kinds of hybrid perovskites as revealed through in-situ grazing incidence wide-angle X-ray scattering(GIWAXS)technique.These experiments were performed in conditions closely mimicking thin film processing and conditions used for thin film solar cell device fabrication,therefore have provided critical information about the mechanism of the phase transformation,its onset,kinetics,as well as the emergence and disappearance of various phases along hybrid perovskite film formation.These measurements capture the overall solidification and conversion process of hybrid perovskite inks into solid films,all of which deeply affect the thin film microstructure and morphology.This paper may be helpful for designing and fabricating high performance perovskite optoelectronics.