Enhanced luminous efficiency of deep red emitting K2SiF6:Mn4+ phosphor dependent on KF ratio for warm-white LED

We demonstrate a simple method of K2SiF6:Mn4+ red phosphor and discuss its promising application in warm-white lighting emitting diodes. The K2SiF6:Mn4+ was synthesized from SiO2 powders through redox reaction in HF/KMnO4 solution. To further increase emission efficiency, KF was introduced in the solution. An intense absorption band in blue and a bright emission in red indicated the phosphor K2SiF6:Mn4+. This phosphor and the synthesis method are expected to be promising candidates for application in white LEDs. •K2SiF6:Mn4+ was synthesized from SiO2 powders through redox reaction in HF/KMnO4 solution.•An intense absorption band in blue and a bright emission in red indicated the phosphor K2SiF6:Mn4+.•This phosphor and the synthesis method are expected to be promising candidates.