Effect of doping charge compensator Li+ on structure and luminescent properties of ZnWO4: Eu3+, Dy3+ phosphor

Abstract

The white-light emitting phosphors ZnWO4:Eu3+,Dy3+ with Li+ as charge compensator were prepared by a hydrothermal method followed with calcination process. And the effects of Li+ doping amount on the structure and luminescent properties of samples were investigated. The results indicate that the introduction of Li+ has little effect on the crystal structure of samples. The particles of the phosphor are approximately spherical in shape, and the size is about 70–100 nm. The main excitation peak of samples is at 297 nm, ascribed to the W6+-O2− charge transfer state (CTS) transition. The emission spectra are composed of blue-green emission band of WO42−, yellow and blue emission peaks of Dy3+, and red emission peaks of Eu3+. With the increase of Li+ doping amount, the emission intensity of Dy3+ firstly increases and then decreases, but the emission intensity of WO42− decreases gradually, and that of Eu3+ remains almost unchanged. When the doping amount of Li+ is 2.5%, the yellow emission intensity of Dy3+ (576 nm) reaches the highest, which is 1.26 times of the uncompensated sample. The emitting color of phosphors can be tuned from the blue-white light through white light to the yellowish-white zone by the increase of Li+ doping amount.