A new path for the synthesis of high quantum efficiency narrow-band-emitting K2TiF6:Mn4+ phosphor for wide-gamut displays

K 2 TiF 6 :Mn 4+ , along with K 2 SiF 6 :Mn 4+ and K 2 GeF 6 :Mn 4+ , is a red phosphor with narrow-band emission for wide-gamut display backlight LEDs. However, its poor absorbance results in low external quantum efficiency, which is a major obstacle for commercial utilization. This paper describes our pursuit of a new path to synthesize the K 2 TiF 6 :Mn 4+ phosphor through cation-exchange-assisted recrystallization achieving excellent performance. The absorbance and the internal and external quantum efficiencies of the as-prepared phosphor reached up to 74.27, 93.06, and 69.09%, respectively; the luminescence intensity at 150 °C was 97.5% of that at 25 °C. The color gamut of white LEDs packaged with optimized K 2 TiF 6 :Mn 4+ covers 98.61% of the NTSC (National Television Standard Committee) color gamut and the amount of phosphor used was reduced by 37.55%, as compared with commercially available LEDs achieving similar performance. These breakthroughs strongly support the commercial implementation of K 2 TiF 6 :Mn 4+ phosphors.