Synthesis and optical properties of a new double-perovskite Rb2KInF6:Mn4+ red phosphor used for blue LED pumped white lighting

High-efficiency narrow-band red phosphor plays a profound part in stimulating illumination quality for white light-emitting diodes (WLEDs). In this work, a series of novel double-perovskite Rb 2 KInF 6 :Mn 4+ red phosphors was successfully prepared by using a facile co-precipitation technique. The crystallization, particle morphology , photoluminescence properties, and thermal quench behavior of the as-synthesized powder samples were investigated systematically. During the illumination with blue ( λ max  = 468 nm) and ultraviolet light ( λ max  = 370 nm), the prepared Rb 2 KInF 6 :Mn 4+ phosphors emited a series of narrowband red signals in the range 590–660 nm with strong zero-phonon line (ZPL) emission. Meanwhile, the optimum Mn 4+ concentration of at the 2 E g → 4 A 2g transitions was also studied. Moreover, the fluorescence decay lifetimes of the prepared Rb 2 KInF 6 :Mn 4+ products were milliseconds. Finally, by coating Rb 2 KInF 6 :Mn 4+ with commercially yellow Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ) phosphors on the commercially available InGaN blue chip, the intense warm white light with suitable correlated color temperature (CCT, 3491 K) and high color-rendering index ( R a , 85.1) can be manufactured at a driving current of 20 mA. All of these consequences point out that the novel double-perovskite red-emitting Rb 2 KInF 6 :Mn 4+ phosphors are promising in the perspective of WLEDs applications.