Synthesis and photoluminescence properties of a red-emitting phosphor, K2SiF6:Mn4+, for use in three-band white LED applications

• We synthesized the red-emitting K2SiF6:Mn4+ phosphors.
• The optimal conditions required to obtain the brightest emission were examined.
• The photoluminescence properties of the three-band white LEDs were examined.

K2SiF6:Mn4+ phosphors were prepared by redox precipitation at room temperature from mixed aqueous solutions of SiO2, HF, KMnO4, and H2O2. The optimal conditions required to obtain the brightest red emission spectra of the K2SiF6:Mn4+ phosphors were examined. The K2SiF6:Mn4+ phosphors emitted deep red light with three strong peaks at 615, 630, and 650 nm under 465 nm excitation, the emission wavelength of a commercial blue LED. K2SiF6:Mn4+ and SrGa2S4:Eu2+ phosphors were used to produce the red and green emission bands under excitation from a commercial blue LED, respectively. The photoluminescence properties of the three-band white LEDs fabricated by coating K2SiF6:Mn4+ and SrGa2S4:Eu2+ phosphors onto the commercial blue LED chip were investigated.