A near UV-excited abnormal broad yellow emission phosphor Ba2CaB2Si4O14:Eu2+ for white-light LEDs

Abstract

Phosphor-converted white LEDs are realized by combining blue InGaN chips with yellow and red emitting materials. Due to the lack of efficient red phosphor materials, we can design a broadband yellow phosphor material containing as many red components as possible. We found an abnormal broadband yellow-emitting Ba2CaB2Si4O14:Eu2+ borosilicate phosphor inspired by natural minerals, which has been synthesized by traditional high temperature solid-state method. The structural information and photoluminescence characteristics of Ba2CaB2Si4O14:Eu2+ were characterized in detail, and applied to the fabrication of white LED devices. Excited by near ultraviolet light at 365 nm, it displays a wide emission band from 400 to 800 nm centered on the 595 nm peak. White LED devices were fabricated by physically mixing the yellow phosphor Ba2CaB2Si4O14:Eu2+ and synthesized blue phosphor BaMgAl10O17:Eu2+ with 365 nm UV chip as excitation. The correlation color temperature (CCT) value and the chromaticity coordinates of the fabricated WLED devices were found to be 5522 K and (0.3293, 0.3036) respectively. In conclusion, Ba2CaB2Si4O14:Eu2+ has great potential in the preparation of near UV excited white LEDs.