Investigation of the structure and photoluminescence properties of Eu3+ ion-activated Y6WxMo(1 −x)O12

A series of Eu3+ ion-activated Y6WxMo(1 − x)O12 polycrystalline powders were synthesized using a solid-state reaction. The crystal structure, ultraviolet-visible and photoluminescence spectra of these compounds were characterized. The structural parameters, electronic structure and orbital population of Y6WO12 and Y6MoO12 were determined by means of density functional theory calculation. The calculated structural parameters agreed well with the experimental values. Both electronic structures and ultraviolet-visible spectra indicated that the band-gap of Y6WO12 is larger than that of Y6MoO12. The WO6 or MoO6 groups in the host lattices could be efficiently excited by near-UV or violet light, and then transferred the energy to the activator Eu3+ ions, resulting in red light dominated emission. It was shown that the ratio of W to Mo in the host lattice had an impact on the luminescence intensity, the purity of the emission light and the decay lifetime strongly. Compounds Y6WxMo(1 − x)O12:Eu could be red-phosphor candidates for WLED devices.