Solar cells based on organic–inorganic hybrid perovskite materials have emerged as the most efficient next-generation thin-film solar cells within just a decade of research and show great promise for commercialization. As control of the thin-film microstructure of the perovskite layer is a key factor enabling high photovoltaic efficiency, good stability, and successful up-scaling of high-quality perovskite thin films for commercialization, a reliable and accurate characterization of the thin-film microstructure is paramount. X-ray diffraction (XRD)-based techniques, including conventional laboratory-based XRD and synchrotron-based grazing-incidence wide-angle x-ray scattering, are widely used to probe the microstructure of photovoltaic perovskite thin films. Nevertheless, it is common for these XRD experiments to be poorly executed and diffraction data to be improperly interpreted. This review focuses on principles of XRD techniques and their application for the characterization of the perovskite thin-film microstructure. Fundamentals of XRD techniques are presented with a strong emphasis on best practices in data collection and analysis. Approaches for the reliable and accurate extraction of microstructural information from diffraction data are discussed, including the need for simulating diffraction patterns. Applications of XRD techniques in characterizing perovskite thin films are demonstrated for both three-dimensional and layered hybrid perovskites, covering various microstructural aspects including phase identification and quantification, texture analysis, microstrain, and macrostrain as well as in situ and operando characterization. The additional subtleties and complexities associated with the XRD characterization of layered hybrid perovskites due to a more complex thin-film microstructure are discussed. Common mistakes and pitfalls that lead to misinterpretation of diffraction data are also highlighted.

中文翻译：

---

光伏钙钛矿的 X 射线衍射：原理和应用

基于有机-无机杂化钙钛矿材料的太阳能电池在短短十年的研究中已成为最高效的下一代薄膜太阳能电池，并显示出巨大的商业化前景。由于控制钙钛矿层的薄膜微观结构是实现高光伏效率、良好稳定性和成功放大高质量钙钛矿薄膜以实现商业化的关键因素，因此对薄膜微观结构进行可靠和准确的表征是最重要的。基于 X 射线衍射 (XRD) 的技术，包括传统的基于实验室的 XRD 和基于同步加速器的掠入射广角 X 射线散射，被广泛用于探测光伏钙钛矿薄膜的微观结构。尽管如此，这些 XRD 实验执行不当和衍射数据解释不当是很常见的。本综述侧重于 XRD 技术的原理及其在钙钛矿薄膜微结构表征中的应用。介绍了 XRD 技术的基础知识，重点介绍了数据收集和分析方面的最佳实践。讨论了从衍射数据中可靠准确地提取微观结构信息的方法，包括模拟衍射图案的必要性。XRD 技术在表征钙钛矿薄膜方面的应用针对三维和层状杂化钙钛矿进行了展示，涵盖了各种微观结构方面，包括相识别和量化、纹理分析、微应变、和宏观应变以及原位和操作表征。讨论了由于更复杂的薄膜微结构而导致的与层状杂化钙钛矿的 XRD 表征相关的其他微妙之处和复杂性。还强调了导致误解衍射数据的常见错误和陷阱。