Photoluminescent properties of the promising red-emitting phosphor LiGd1−xEux(MoO4)2 for WLEDs

Abstract

A series of LiGd1−xEux(MoO4)2 (x=0.01–1) red-emitting phosphors were synthesized by the conventional solid-state reaction method. XRD was used to determine the structure of the samples, showing that the products are single phased with sheelite-like structure. The photoluminescent properties were characterized by a fluorescence spectrophotometer and the effects of the calcination temperature, the holding time as well as the doping concentration, especially the low doping concentration of Eu3+, were discussed. Upon excitation with 395nm, the LiGd(MoO4)2:Eu3+ phosphors show strong red emission lines at 617nm which are ascribed to the forced electric dipole transition 5D0–7F2 of Eu3+. The appropriate calcination temperature and holding time are 900°C and 5h, respectively. With increasing Eu3+ doping concentration, the emission intensity of the samples is enhanced and no obvious concentration quenching occurs. The prepared samples are potential red phosphors for near UV White LEDs application.