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

Abstract

Ce³⁺ doped aluminosilicate phosphors (Ca_2−xAlMg_0.5Si_1.5O₇:xCe³⁺, x = 0.015–0.075) for white NUV w-LEDs were synthesized by a solid-state reaction method at 1250 °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 ²D_3/2 → ²F_7/2 and ²F_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 (T₅₀ = 230 °C). We obtained bright blue-violet light by pumping the sample with NUV light (λ ≈ 365 nm), which suggests that this material has the potential for application as a NUV converting blue-violet phosphor for the NUV w-LEDs.