Synthesis and characterization of novel red emitting nanocrystal Gd6WO12:Eu3+ phosphors

Novel nanosized Gd6WO12:Eu3+ phosphors were synthesized via a co-precipitation reaction. The crystal structure and morphology of the phosphors were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). It was found that the resultant powders show a regular and sphere-like shape with average particle size of 60 nm. Intrinsic red emission originating from Eu3+ was observed while excited at the W6+→O2− and Eu3+→O2− charge transfer bands or f–f absorption bands. The color coordinates of the phosphors were calculated to be x=0.625, y=0.375. The concentration dependence of the luminescence was studied, and optimum doping concentration for obtaining maximum emitting intensity was confirmed to be around 12 mol%. It was also found that the electric dipole–dipole interaction plays an important role for quenching luminescence of Eu3+.