Gd1-x-Eux (x = 0.2, 0.3, 0.4, 0.5) doped tungsten oxide red-emitting phosphor was prepared using solution chemistry. The phase, morphology, and luminescence characteristics of the obtained phosphors were compared with those of oxide obtained from general solid-state reaction processes. The suitability of the 600oC calcination temperature for producing W-Eu-Gd-O mixtures was confirmed by TG weight loss measurements. The results show that the phase development behaviors and morphologies differ from those of general solid-state processes. Whereas the general process developed only one phase, the solution process produced various phases, such as Gd2WO6, Gd2W2O9, and Gd2(WO4)3, from the heat treatment of the oxide mixture at 1000oC. The phosphor grain size can be controlled by this solution chemistry process. The emission behaviors of the synthesized phosphors strongly depend on the phase structures.

Keywords: solution chemistry, red emitting, phosphors.