Abstract
Lead halide perovskite nanocrystals (NCs) have attracted great attention owing to the simplicity of their synthesis and excellent defect-tolerance nature. They not only demonstrate outstanding optical and electronic properties, but also hold substantially ionic lattices with some counterintuitive structural features that are significantly different from conventional colloidal semiconductor NCs such as CdSe and InP. In this Review, we summarize and assess the recent advances in the understanding of structural characteristics of lead halide perovskite NCs. We specifically focus on the role of intrinsic defects, NC size, dopants, alloying, and external stimuli in affecting their structure. Moreover, we highlight the use of atomic resolution imaging technique in investigating their microstructural characteristics. Finally, we discuss open questions and present our perspectives on future research directions in the exciting field of science.