KBaPO4:Ln (Ln=Eu, Tb, Sm) phosphors for UV excitable white light-emitting diodes

This letter reports the novel three emission bands based on phosphate host matrix, KBaPO4 doped with Eu2+, Tb3+, and Sm3+ for white light-emitting diodes (LEDs). The phosphors were synthesized by solid-state reaction and thermal stability was elucidated by measuring photoluminescence at higher temperatures. Eu2+-doped KBaPO4 phosphor emits blue luminescence with a peak wavelength at 420 nm under maximum near-ultraviolet excitation of 360 nm. Tb3+-doped KBaPO4 phosphor emits green luminescence with a peak wavelength at 540 nm under maximum near-ultraviolet excitation of 370 nm. Sm3+-doped KBaPO4 phosphor emits orange–red luminescence with a peak wavelength at 594 nm under maximum near-ultraviolet excitation of 400 nm. The thermal stabilities of KBaPO4:Ln (Ln=Eu2+, Tb3+, Sm3+), in comparison to commercially available YAG:Ce3+ phosphor were found to be higher in a wide temperature range of 25–300 °C.