Photoluminescence properties of Sm3+-doped LiY(MoO4)2 red phosphors

A series of novel Sm3+-doped LiY(MoO4)(2) red phosphors under the UV excitation were synthesized by solid state reaction at 800 degrees C for 7 h. The data measured by X-ray diffraction (XRD) indicated that the samples were all pure phases of LiY(MoO4)(2). Their excitation spectra had a broad band ranging from 250 to 350 nm and several sharp peaks. The centers of the peaks were located at about 365 nm (H-6(5/2)-> D-4(3/2)), 378 nm (H-6(5/2)-> P-6(7/2)), 406 nm (H-6(5/2)-> F-4(7/2)), 420 nm (H-6(5/2)-> P-6(5/2)), 442 nm (H-6(5/2)->(4)G(9/2)), 471 nm (H-6(5/2)-> I-4(13/2)) and 482 nm (H-6(5/2)-> I-4(9/2)), respectively. The strongest emission was excited by 406 nm, and the main emissions were located at 568 nm ((4)G(5/2)-> H-6(5/2)), 610 nm ((4)G(5/2)-> H-6(7/2)), 649 nm ((4)G(5/2)-> H-6(9/2)) and 710 nm ((4)G(5/2)-> H-6(11/2)). Photoluminescence properties were determined for various concentrations of Sm3+-doped LiY(MoO4)(2) host, and the luminescence intensity had the best value when x=0.02 in LiY1-x(MoO4)(2):xSm(3+).