Air stable and highly efficient Bi 3+ -doped Cs 2 SnCl 6 for blue light-emitting diodes.

Cs 2 SnCl 6 perovskite 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 Bi 3+ -doped Cs 2 SnCl 6 (Cs 2 SnCl 6 :Bi 3+ ) with enhanced luminescence were synthesized by a solution-phase route. The results show that the initial concentration of Sn 2+ can adjust the nucleation density and the quality of the crystal nucleus growth, which will affect the Bi 3+ doping amount, crystal morphology, and photophysical properties of Cs 2 SnCl 6 :Bi 3+ . Cs 2 SnCl 6 :Bi 3+ 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 [Bi Sn 4+ 3+ + V Cl ] defects caused by the Bi 3+ doping. The blue LED based on the Cs 2 SnCl 6 :Bi 3+ 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 Cs 2 SnCl 6 :Bi 3+ for blue LED applications.