Abstract
Metal halide perovskite (MHP) single crystals are promising candidates for photovoltaics and related optoelectronic devices. They afford optical and charge transport properties superior to those of their polycrystalline counterparts. Despite this advantage, MHP single crystals are less widely adopted. Traditional bulk growth methods do not lend single-crystal MHPs to device integration as readily as their polycrystalline analogues, which are amenable to a multitude of approaches for deposition and growth. Fortunately, diverse shape-control approaches for MHP single crystals have been recently reported, enabling tunable optoelectronic properties and expanding the potential for single-crystal applications. In this review, we summarize recent developments in the shape control of MHP single crystals, including those pertaining to microcrystals, single-crystal thin films, nano/microplates, nano/microrods, and nanocrystals. We highlight strategies for optimizing the synthesis of these crystals to achieve targeted materials properties and device performance. This review aims to guide the future of shape design in MHP single crystals for various optoelectronic applications.