Broadband emission of double perovskite CsNaAgInBiCl:Mn for single-phosphor white-light-emitting diodes.

In this Letter, we report the broadband photoluminescence of lead-free double perovskite CsNaAgInBiCl:Mn. Under ultraviolet excitation, the white phosphor shows two emission peaks at 550 nm and 610 nm from self-trapped exciton and doped Mn ions, respectively, leading to a broad emission spectrum over the whole visible spectrum suitable for lighting application. The white-light-emitting diodes exhibit high light quality with CIE coordinates (0.38, 0.42) and color rendering index of 82.6. The mechanism of luminescence of this double perovskite is also discussed in this Letter.