Highly efficient and stable Cs 3 Mn 0.93 Zn 0.07 Br 5 @SiO 2 for wide color gamut backlight displays.

Mn-based perovskites have become a new candidate material for backlight display applications. However, low efficiency and poor stability are the key problems limiting the application of Mn-based perovskites. In this work, Zn-doped and SiO 2 -encapsulated Cs 3 MnBr 5 , denoted as Cs 3 Mn 0.93 Zn 0.07 Br 5 @SiO 2 (CMZBS), was successfully synthesized to improve the photoluminescence quantum yield (PLQY) and stability. After Zn doping, the PLQY increased from 51% to 72% due to the reduction in the energy transfer between [MnBr 4 ] 2- . The PLQY can be further improved to 80% after coating SiO 2 . Compared with Cs 3 MnBr 5 (CMB), CMZBS showed better stability against thermal, air, light, and polar solvents (ethanol and isopropanol). In addition, a white LED (WLED) device with a CIE of (0.323, 0.325) was fabricated by integrating CMZBS and the red phosphor K 2 SiF 6 :Mn 4+ on a 465 nm blue GaN chip, which exhibited a high luminous efficiency of 92 lm W -1 and excellent stability, demonstrating its great potential application in wide color gamut displays.