A novel near-ultraviolet (NUV) converting blue-violet Ca2-xAlMg0.5Si1.5O7:xCe3+ phosphor for white light-emitting-diodes (w-LEDs)

Ce3+ doped aluminosilicate phosphors (Ca2-xAlMg0.5Si1.5O7:xCe(3+), x = 0.015-0.075) for white NUV w-LEDs were synthesized by a solid-state reaction method at 1250 degrees C. The as-prepared samples were characterized by XRD and fluorescence spectrophotometry; the obtained XRD results show that the target phase was synthesized and doping with Ce3+ did not result in an impurity phase. The as-prepared phosphors exhibit a strong blue-violet emission under the near-ultraviolet radiation excitation. Corresponding fitting results show the emission spectra contain two distinct single bands, which come from the transition of D-2(3/2) -> F-2(7/2) and F-2(5/2) of the Ce3+ ion. The colorimetric coordinates of the sample with x = 0.03 are (0.1574, 0.0359), located in the blue-violet region. In addition, the sample exhibits high external quantum efficiency (EQE = 37.3%) and excellent thermal stability (T-50 = 230 degrees C). We obtained bright blue-violet light by pumping the sample with NUV light (lambda = 365 nm), which suggests that this material has the potential for application as a NUV converting blue-violet phosphor for the NUV w-LEDs.