High-quality bulk hybrid perovskite single crystals within minutes by inverse temperature crystallization

Single crystals of methylammonium lead trihalide perovskites (MAPbX(3); MA = CH3NH3+, X = Br- or I-) have shown remarkably low trap density and charge transport properties; however, growth of such high-quality semiconductors is a time-consuming process. Here we present a rapid crystal growth process to obtain MAPbX(3) single crystals, an order of magnitude faster than previous reports. The process is based on our observation of the substantial decrease of MAPbX(3) solubility, in certain solvents, at elevated temperatures. The crystals can be both size- and shape-controlled by manipulating the different crystallization parameters. Despite the rapidity of the method, the grown crystals exhibit transport properties and trap densities comparable to the highest quality MAPbX(3) reported to date. The phenomenon of inverse or retrograde solubility and its correlated inverse temperature crystallization strategy present a major step forward for advancing the field on perovskite crystallization.