Photoluminescence Properties and Energy Transfers in the Novel LiYMgWO6: Dy3+, Tm3+

Abstract

A series of Dy3+/Tm3+ single doped and co-doped double perovskite-structure compound LiYMgWO6 (LYMW) are prepared by a solid-state route. The structure and photoluminescence properties have been unraveled by combining experiments and first-principles calculations. The crystal structure was determined to be a monoclinic structure with space groups P21. Under the ultraviolet (UV) excitation, Dy3+ and Tm3+ single doped LYMW samples emit yellowish-white and blue light, respectively. For Dy3+ and Tm3+ co-doped LYMW, the emission can be tuned from blue to white light and eventually to yellow through energy transfers by varying the Dy3+ and Tm3+ concentrations. The sample with 3%Dy3+ and 3%Tm3+ has chromaticity coordinates (0.3405, 0.3378), which are nearest to the ideal white light (0.33,0.33). The energy transfer mechanism is verified to be the quadrupole-quadrupole interaction. The temperature-dependent photoluminescence (PL) spectra show that LYMW: Dy3+, Tm3+ exhibits good thermal stability.