Air stable and highly efficient Bi3+-doped Cs2SnCl6for blue light-emitting diodes

Abstract

Cs2SnCl6perovskite has recently attracted attention as a promising optoelectronic material owing to its better stability and reduced toxicity than its lead counterparts. However, its luminescence performance hardly satisfies the requirements. Hence, a series of Bi3+-doped Cs2SnCl6(Cs2SnCl6:Bi3+) with enhanced luminescence were synthesized by a solution-phase route. The results show that the initial concentration of Sn2+can adjust the nucleation density and the quality of the crystal nucleus growth, which will affect the Bi3+doping amount, crystal morphology, and photophysical properties of Cs2SnCl6:Bi3+. Cs2SnCl6:Bi3+shows excellent stability in the atmosphere with a photoluminescence (PL) of around 456 nm and a photoluminescence quantum yield (PLQY) of 31%. The luminescence performance results from [BiSn4+3++ VCl] defects caused by the Bi3+doping. The blue LED based on the Cs2SnCl6:Bi3+phosphor exhibits a long life of about 120 h and a Commission Internationale de L'Eclairage (CIE) color coordinates of (0.14, 0.11). This work demonstrates a strategy for Bi-doped perovskites with good stability. This investigation will facilitate the development of Cs2SnCl6:Bi3+for blue LED applications.