Synthesis and luminescence properties of Ln 3+ (Ln 3+ = Er 3+, Sm 3+)-doped barium lanthanum tungstate BaLa 2WO 7 phosphors

Abstract

BaLa 2WO 7 phosphors activated with the trivalent rare-earth Er 3+ and Sm 3+ were synthesized via a solid-state reaction using a vibrating-mill method, and their luminescence properties were investigated. Er 3+-doped BaLa 2WO 7 and Sm 3+-doped BaLa 2WO 7 emit bright green and reddish-orange light, respectively. The photoluminescence investigations revealed that the phosphors exhibit apparent characteristic emissions from the 2 H 11 / 2 and 4 S 3 / 2 state, respectively, to the 4 I 15 / 2 ground state for Er 3+, and 4 G 5 / 2 to 6 H 5 / 2 , 7 / 2 , 9 / 2 states for Sm 3+ under near-UV excitation. The green emission of the Er 3+-doped BaLa 2WO 7 phosphor had CIE chromaticity coordinates (0.249, 0.717) with a dominant wavelength of 546 nm and a color purity of 92%. The Sm 3+-doped BaLa 2WO 7 phosphor had color coordinates (0.558, 0.441), a dominant wavelength of 606 nm, and 94% color purity. The sharp emission peaks and excellent luminescence properties show that BaLa 2WO 7 is a suitable host for rare-earth-doped phosphors, which may be suitable for optical applications.