Synthesis and Luminescence Properties of Novel Ce3+- and Eu2+-Doped Lanthanum Bromothiosilicate La3Br(SiS4)(2) Phosphors for White LEDs

Abstract

Novel Ce3+- and Eu2+-doped lanthanum bromothiosilicate La3Br(SiS4)(2):Ce3+ and La3Br(SiS4)(2):Eu2+ phosphors were prepared by solid-state reaction in an evacuated and sealed quartz glass ampule. The La3Br(SiS4)(2):Ce3+ phosphor generates a cyan emission upon excitation at 375 nm, whereas the La3Br(SiS4)(2):Eu2+ phosphor could be excited with extremely broad range from UV to blue region (300 to 600 nm) and generates a reddish-orange broadband emission centered at 640 nm. In addition, thermal luminescence properties of La3Br(SiS4)(2):Ce3+ and La3Br(SiS4)(2):Eu2+ phosphors from 20 to 200 degrees C were investigated. The combination of a 450 nm blue InGaN-based LED chip with the red-emitting La3Br(SiS4)(2):Eu2+ phosphor, and green-emitting BOSE:Eu2+ commercial phosphor produced a warm-white light with the CRI value of similar to 95 and the CCT of 5,120 K. Overall, these results show that the prepared phosphors may have potential applications in pc-WLED.