Intense Red-Emitting NaYSiO4: Eu3+, Mo6+ Phosphors for White Light-Emitting Diodes

Abstract

Novel red phosphors Na(Y1-xEux)(Si1-yMoy)O-4 were developed for white light emitting diode applications and their luminescent properties were investigated in detail. The results indicated that NaY1-xEuxSiO4 samples can be effectively excited by near-ultraviolet light (393 nm) and the introduction of Mo6+ strongly enhanced the emission intensity of Eu3+ when samples were excited under 393 nm, which was ascribed to the improvement of absorption intensities of F-7(0) -> L-5(6) transitions. Besides, the quantum efficiencies of a series of Na(Y1-xEux)(Si1-yMoy)O-4 samples were calculated according to the average decay lifetimes. The composition-optimized Na(Y0.7Eu0.3)(Si0.7Mo0.3)O-4 sample exhibited the red light emission brightly with the chromaticity coordinates of (0.66, 0.34), whose integral intensity was calculated to be about 2.16 times of that of the commercial red phosphor Y2O3: Eu3+. Thus, Na(Y1-xEux)(Si1-yMoy)O-4 can be as red-phosphor candidates for white light-emitting diodes devices. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3600350] All rights reserved.