Synthesis and luminescence properties of Ln3+ (Ln3+ = Er3+, Sm3+)-doped barium lanthanum tungstate BaLa2WO7 phosphors

BaLa2WO7 phosphors activated with the trivalent rare-earth Er3+ and Sm3+ were synthesized via a solid-state reaction using a vibrating-mill method, and their luminescence properties were investigated. Er3+-doped BaLa2WO7 and Sm3+-doped BaLa2WO7 emit bright green and reddish-orange light, respectively. The photoluminescence investigations revealed that the phosphors exhibit apparent characteristic emissions from the 2H(11/2) and S-4(3/2) state, respectively, to the I-4(15/2) ground state for Er3+, and (4)G(5/2) to H-6(5/2.7/2.9/2) states for Sm3+ under near-UV excitation. The green emission of the Er3(3+)-doped BaLa2WO7 phosphor had CIE chromaticity coordinates (0.249, 0.717) with a dominant wavelength of 546 nm and a color purity of 92%. The Sm3+-doped BaLa2WO7 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 BaLa2WO7 is a suitable host for rare-earth-doped phosphors, which may be suitable for optical applications. (C) 2011 Elsevier B.V. All rights reserved.