BaCa13Mg2(SiO4)8: Ce3+ — A blue phosphor with high brightness, high internal quantum efficiency and excellent thermal stability for w-LEDs

Abstract

In this paper, a series of Ce3+ ions doped BaCa13Mg2(SiO4)8 blue phosphors were synthesized via a conventional high-temperature solid-state method. Calculations by DFT confirmed that the BaCa13Mg2(SiO4)8 host had a suitable band gap for doping rare earth ions. In terms of luminescence performance, BaCa13Mg2(SiO4)8: Ce3+ blue phosphor with an optimal excitation wavelength of 365 nm can effectively absorb light from 310 to 400 nm and produce a wide emission band centered at 440 nm with an internal quantum efficiency of 71.39%. Based on the analysis of the structure and Gaussian fitting spectra, the Ce3+ ion can occupy all of the Ba2+ and Ca2+ ion lattice positions. After charge compensation by K+ ions, the emission intensity can be increased by 36.8%, and the emission intensity at 140 °C can still maintain 88.7% compared with that at room temperature. Under 365 nm excitation, the integral intensity of the emission spectrum BaCa13Mg2(SiO4)8: 3% Ce3+, 3% K+ sample can reach 90.4% of that of the commercial blue phosphor BaMgAl10O17: Eu2+. When BaCa13Mg2(SiO4)8: Ce3+ phosphors are combined with green (Ba, Sr)2SiO4: Eu2+ phosphors and red CaAlSiN3: Eu2+ phosphors on a 365 nm UV-LED chip, bright LED devices with a correlated color temperature of 4172 K can be obtained. The results show that the blue phosphor BaCa13Mg2(SiO4)8: Ce3+ has great potential for w-LEDs applications.