Energy transfer mechanism and optical properties of Eu³⁺, Dy³⁺ co-doped LaVO₄ phosphors

The synthesis of aseries of orange-red Eu-doped LaVO₄:0.05Dy³⁺ phosphors with a pH value of 9 by a hydrothermal method, varying the Eu³⁺ concentration. It was found that the optimal concentration of Eu³⁺ for enhanced luminescence in LaVO₄:0.05Dy³⁺, xEu³⁺ is 0.07. A detailed analysis of the structure and morphology of the crystals, coupled with an in-depth examination of the photoluminescence(PL) behavior of the phosphor, led to the conclusion that energy transfer between Dy³⁺ and Eu³⁺ facilitates the luminescence. Moreover, low color temperature, high color rendering index(CRI), and orange-red LED devices were effectively fabricated utilizing LaVO₄:0.05Dy³⁺, 0.07Eu³⁺ samples. The energy bands, density of states, and optical properties of the m-LaVO₄ crystals were analyzed by first-principle counting of the crystals using density-functional theory. The results demonstrate that the co-doping of Eu³⁺ and Dy³⁺ can effectively reduce the forbidden band width of m-LaVO₄.