Preparation and optical properties of orange-red-emitting BiLaWO6:Sm3+ phosphors

Abstract

Novel orange-red-emitting-BiLaWO6:xSm3+ phosphors were synthesized through the solid-state reaction technique. X-ray diffraction (XRD) revealed that the samples have a single phase with monoclinic with space group C2/m (12). Scanning electron microscopy (SEM) revealed that the particle size was distributed in the range of 0.5–1 µm. The BiLaWO6:Sm3+ phosphor can be excited at 478 nm, and presented four distinctly typical peaks, which were ascribed to the transitions of Sm3+ ion: 4G5/2 to 6HJ (J = 5/2, 7/2, 9/2, and 11/2). The effects of concentration on luminescence intensities of BiLaWO6:xSm3+ showed the optimal doping concentration (x) was 0.05 mol. Meanwhile, the corresponding critical transfer distance was around 17.13 A. The thermal quenching temperature (T0.5 = 393 K) was evaluated from 300 K to 480 K and the activation energy (Ea) was about 0.32 eV. The chromaticity coordinate was (0.576, 0.401) at the optimal concentration, presenting at the orange-red color region in the 1931 CIE diagram. The results indicated that the phosphors have potential applications in white light-emitting diodes (w-LED).