Colloidal synthesis of monolayer-thick formamidinium lead bromide perovskite nanosheets with a lateral size of micrometers

Abstract

This communication describes a facile hot-injection method for the synthesis of novel micrometer-size formamidinium lead bromide perovskite (FAPbBr₃) nanosheets of monolayer thickness (around 2.4 nm). Due to the strong quantum confinement effect, the as-synthesized large-sized perovskite nanosheets displayed an unprecedented extremely blue-shifted first sharp excitonic absorption peak at 435 nm and an emission peak at 437 nm, as compared to that of bulk FAPbBr₃ crystals at 551 nm.