Crystal field optimization and fluorescence enhancement of a Mn4+-doped fluoride red phosphor with excellent stability induced by double-site metal ion replacement for warm WLED

The effective double-site metal ion replacement strategy is adopted to synthesize the K 0.6 Ba 0.7 Si 0.5 Ge 0.5 F 6 :Mn 4+ red phosphor with efficient water and thermal stability for high-performance warm WLED.