Controlled Synthesis of Perovskite Nanocrystals at Room Temperature by Liquid Crystalline Templates.

Perovskite nanocrystals (PNCs) are promising active materials because of their outstanding optoelectronic properties, which are finely tunable via size and shape. However, previous synthetic methods such as hot-injection and ligand-assisted reprecipitation require a high synthesis temperature or provide limited access to homogeneous PNCs, leading to the present lack of commercial value and real-world applications of PNCs. Here, we report a room-temperature approach to synthesize PNCs within a liquid crystalline antisolvent, enabling access to PNCs with a precisely defined size and shape and with reduced surface defects. We demonstrate that elastic strains and long-range molecular ordering of the liquid crystals play a key role in not only regulating the growth of PNCs but also promoting high surface passivation of PNCs with ligands. The approach is a simple, rapid, and room-temperature process, yet it enables access to highly homogeneous PNCs on a mass scale with substantially reduced surface defect states leading to significantly enhanced optoelectronic features. Our results provide a versatile and generalizable strategy to be broadly compatible with a range of nanomaterials and other synthetic methods such as ligand exchange and microfluidic processes.