Emerging Conductive Atomic Force Microscopy for Metal Halide Perovskite Materials and Solar Cells

Abstract Metal halide perovskite materials, benefiting from a combination of outstanding optoelectronic properties and low‐cost solution‐preparation processes, show tremendous potential for optoelectronics and photovoltaics. However, the nanoscale inhomogeneities of the electronic properties of perovskite materials cause a number of difficulties, such as recombination, stability, and hysteresis, all of which seriously restrict device performance. Scanning probe microscopy, as a high‐resolution imaging technique, has been widely used to connect local properties and micro‐area morphologies to overall device performance. Conductive atomic force microscopy (C‐AFM) can realize a real‐space visualization of topography coupled with optoelectronic properties on a microscopic scale and thereby is uniquely suited to probe the local effects of perovskite materials and devices. The fundamental principles, alternative operation modes, and development of C‐AFM are comprehensively reviewed, and applications in perovskite solar cells (PSCs) for electronic transport behavior, ion migration and hysteresis, ferroelectric polarization, and facet orientation investigation are discussed. A comprehensive understanding and summary of up‐to‐date applications in PSCs is beneficial to further fully exploit the potential of such an emerging technique, so as to provide a novel and effective approach for perovskite materials analysis.