Jin Bowen, Ming Yidong, Liang Zihui, Wang Kai, Wu Congcong
Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, School of Materials Science and Engineering, Hubei University, Wuhan 430062, China.
Department of Materials Science and Engineering, Penn State, University Park, Pennsylvania 16802, United States.
J Phys Chem Lett. 2022 Aug 11;13(31):7236-7242. doi: 10.1021/acs.jpclett.2c02060.
Perovskite grain size has been used as one of the indicators to evaluate the morphological quality of perovskite films. Large grain size is customarily regarded as an indicator of high photovoltaic performance because it is thought to result in superior charge carrier transport properties due to less carrier scattering by the grain boundaries (GBs). Consequently, the characterization of perovskite grain size has become routine in perovskite solar cell research, and large grain size is in general pursued. However, grain size estimation relying on the prevailing methods, such as scanning electron microscopy (SEM), can be viewed only as "apparent grain size", which is incomplete or possibly wrong for evaluating GB distribution. To avoid the pitfalls and advocate for accurate methodologies in identifying perovskite grain size, this Viewpoint highlights the pitfalls by demonstrating specific examples and then provides an appropriate platform to accurately evaluate perovskite grain information.
钙钛矿晶粒尺寸已被用作评估钙钛矿薄膜形态质量的指标之一。大晶粒尺寸通常被视为高光伏性能的指标，因为人们认为由于晶界（GBs）对载流子的散射较少，大晶粒尺寸会导致优异的电荷载流子传输特性。因此，钙钛矿晶粒尺寸的表征已成为钙钛矿太阳能电池研究中的常规操作，人们普遍追求大晶粒尺寸。然而，依靠扫描电子显微镜（SEM）等常用方法进行的晶粒尺寸估计只能被视为“表观晶粒尺寸”，对于评估晶界分布来说是不完整的，甚至可能是错误的。为了避免这些陷阱并倡导在确定钙钛矿晶粒尺寸时采用准确的方法，本观点通过展示具体示例突出了这些陷阱，然后提供了一个准确评估钙钛矿晶粒信息的合适平台。
