X-Ray Ptychographic Tomography of Morphological Defects in Metal Halide Perovskites

Perovskite-based solar cells (PSCs) are considered a disruptive photovoltaic technology with their power conversion efficiency rapidly climbing to certified 25.7%. To exploit its maximum potential, the microstructure and morphological defects of metal halide perovskites (MHPs) must be fully characterized, understood, and then tailored. Recently, X-ray ptychography has emerged as a new imaging technique that can combine advantages of coherent X-ray diffractive imaging and conventional scanning transmission X-ray microscopy techniques. With the latest development, it can achieve 3D tomography of materials structures with a high resolution of sub-10 nm while it may cause little damage on soft material samples compared to another characterization tool. Here I will present our recent achievement leveraging X-ray ptychographic imaging to characterize MHPs, revealing various 3D structural defects fully or partially buried underneath the surface. We demonstrate X-ray ptychography as a new, powerful, non-intrusive characterization method for illuminating the complete microstructure of perovskites for energy applications.<br/><br/><b>References</b><br/>[1] Y. Zhang, M. Hao, H. Zhou, J. Deng, Y. Zhou, J. Energy Chem. <i>in press</i>.