Tunable dual-emission of Sb, HoCo-doped CsNaScClsingle crystals for light-emitting diodes.

Lead-free halide double perovskites are considered as one of the most promising materials in optoelectronic devices, such as solar cells, photodetectors, and light-emitting diodes (LEDs), due to their environmental friendliness and chemical stability. However, the extremely low photoluminescence quantum yield (PLQY) of self-trapped excitons (STEs) emission from lead-free halide double perovskites impedes their applications. Herein, Sbions were doped into rare-earth-based double perovskite CsNaScClsingle crystals (SCs), resulting in a large enhancement of PLQY from 12.