Highly efficient double perovskite (Bi,Gd)-codoped Cs2Ag0.4Na0.6InCl6 phosphors for warm white LEDs

Bi-doped lead-free double perovskite Cs2Ag0.6Na0.4InCl6 phosphors have been proved to be effective for use in white LEDs. To further improve the luminescence effect of this promising material, Bi3+/Gd3+ co-doped lead-free perovskite Cs2Ag0.6Na0.4InCl6 phosphors were successfully synthesized using the oil bath method. The quantum efficiency of orange-emitting Cs2Ag0.6Na0.4InCl6:1% Bi3+ was effectively improved from 79.72% to 87.57% by co-doping Gd3+ ions. White LEDs were prepared by mixing the synthesized phosphor Cs2Ag0.40Na0.60InCl6: 1%Bi3+,10%Gd3+ and commercial blue phosphor BaMgAl10O17:Eu2+. Excellent warm white LEDs with colour coordinates (0.3464, 0.3224), colour rendering index of 93.9, and colour temperature of 4818 K were produced. The results of this study provide a meaningful reference for new lead-free halide perovskite luminescent material systems.