High-brightness Sm3+-doped La0.67Mg0.5W0.5O3 red phosphor for NUV light-emitting diodes application

Abstract

Red phosphors La0.67(1−x)Mg0.5W0.5O3:xSm3+ (x = 0.01, 0.02 0.03, 0.04, 0.05, 0.06, and 0.07) were synthesized by a conventional solid-state reaction (SSR) route. The X-ray diffraction (XRD) patterns, photoluminescence spectra, ultraviolet–visible reflection spectroscopy, decay time and the International Commission on Illumination (CIE) chromaticity coordinates of these compounds were characterized and analyzed. The emission spectra of the La0.67(1−x)Mg0.5W0.5O3:xSm3+ phosphors consisted of some sharp emission peaks of Sm3+ ions centered at 563 nm, 601 nm, 646 nm. The strongest one is located at 646 nm due to 4G5/2–6H9/2 transition of Sm3+, generating bright red light. The optimum dopant concentration of Sm3+ ions in La0.67(1−x)Mg0.5W0.5O3:xSm3+ is 2 mol%. The CIE chromaticity coordinates of the La0.67(1−x)Mg0.5W0.5O3:xSm3+ phosphors were located in the red region. The La0.67(1−x)Mg0.5W0.5O3:xSm3+ phosphors may be potentially used as red phosphors for white light-emitting diodes.