High-Efficiency Red-Emitting Phosphor of Li_0.5La_0.5SrMgWO₆: Mn⁴⁺, Pr³⁺

Abstract

The 400–500 nm blue light and 630–750 nm red light play crucial roles in plant cultivation. In this work, a high efficiency red-emitting phosphor, Li0.5La0.5SrMgWO6:Mn4+, Pr3+, was synthesized through the solid-state reaction technique. The absorption and excitation spectra were measured, indicating that 467 nm was an suitable excitation wavelength for this material. Upon excitation with a 467 nm LED, the fluorescence characteristics were evaluated, revealing dual-band red emission peaks located at 621–654 nm and 695–710 nm. The quantum efficiency and pumping slope efficiency were measured to be 63% and 35%, respectively. Based on energy level theory and Tanabe-Sugano theory, the dual-band fluorescence mechanism was analyzed, revealing that cross relaxation phenomenon contributed to the high quantum efficiency. The temperature sensing property was also demonstrated. The relative sensitivity (Sr) exhibited a significant change from 0.05% K−1 to 0.85% K−1 with different temperatures. The phosphor’s high efficiency and exceptional temperature property confer it with extensive potential applications in the fields of plant cultivation and display technology.