Broadband emission of Lu3Mg2GaSi2O12: Ce3+, Sm3+ phosphors and their potential application for w-LEDs

Abstract Herein, Lu3Mg2GaSi2O12: Ce3+/Sm3+ (LMGS) phosphors with a garnet structure were synthesized by a high-temperature solid-phase reaction method, and their potential application in w-LEDs was evaluated. In this study, the crystal structure of the phosphor was determined using the Rietveld method and XRD pattern analysis, while the luminescence performance was characterized by the relevant PL spectrum, and then, the energy transfer (ET) mechanism was explored. When subjected to an excitation at a wavelength of 450 nm, the introduction of Sm3+ ions into LMGS: 0.015Ce3+ broadens the broadband emission of Ce3+ ions owing to the co-excitation and ET of Ce3+ and Sm3+. A continuous and controlled variation in the Sm3+ doping concentration facilitates the tuning of color coordinate from green to yellow. The maximum Ce3+→Sm3+ energy transfer efficiency of the sample was 55.64 %. From the viewpoint of practical applications, the sample exhibited excellent thermal stability and water resistance. After combining the LMGS: 0.015Ce3+, 0.03Sm3+ sample with a commercial red phosphor and a blue chip, a warm white LED with a color rendering index of 86.6 and color temperature of 3592 K can be obtained.