Optimized photoluminescence of red phosphor K2LiAlF6:Mn4+ synthesized by a cation-exchange method

Red phosphor K 2 LiAlF 6 :Mn 4+ has been synthesized by a cation-exchange method in HF solution. To optimize their optical properties, phosphors were synthesized using different reaction conditions. The K 2 LiAlF 6 :0.5%Mn 4+ synthesized at 20°C for 4 h shows the highest luminescence intensity. The temperature-dependent emission intensity of the phosphor was investigated, and it was found to exhibit good thermal stability, making it a promising red phosphor candidate for warm WLEDs.