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

Abstract

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 <i>via</i> 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.