The 3D-structure-mediated growth of zero-dimensional Cs4SnX6 nanocrystals

Innovations in approaches to synthesize high-quality lead perovskite nanocrystals have enabled the prosperous development of nanocrystal-based optoelectronic devices in recent years. However, the transfer of these approaches to tin perovskite nanocrystals, which are the most promising lead-free perovskite candidates, remains unsuccessful. Herein, based on a three-dimensional (3D)-structure-mediated approach, monodispersed and highly luminescent inorganic zero-dimensional (0D) tin perovskite nanocrystals (NCs) are synthesized. The crystal growth kinetics are revealed via tracking the intermediate structures and using theoretical simulations. The luminescence quantum yield of Cs4SnBr6 NCs is as high as 52%, which is the highest value for inorganic tin perovskite NCs. Cs4SnI6 NCs with a luminescence quantum yield of 27% are synthesized, which is 35 times higher than previous results. Based on the Cs4SnBr6 NCs, an ultraviolet-light-pumped white-light-emitting device (WLED) with an excellent color-rendering index of 92 is fabricated.