Synthesis of Gd2Ti2O7:Eu3+, V4+ phosphors by sol-gel process and its luminescent properties

A red-emitting phosphor material, Gd2Ti2O7:Eu3+, V4+, by added vanadium ions is synthesized using the sol-gel method. Phosphor characterization by high-resolution transmission electron microscopy shows that the phosphor possesses a good crystalline structure, while scanning electron microscopy reveals a uniform phosphor particle size in the range of 230-270 nm. X-ray photon electron spectrum analysis demonstrates that the V4+ ion promotes an electron dipole transition of Gd2Ti2O7:Eu3+ phosphors, causing a new red-emitting phenomenon, and CIE value shifts to x=0.63, y=0.34 (a purer red region) from x=0.57, y=0.33 (CIE of Gd2Ti2O7:Eu3+). The optimal composition of the novel red-emitting phosphor is about 26% of V4+ ions while the material is calcinated at 800  °C. The results of electroluminescent property of the material by field emission experiment by CNT-contained cathode agreed well with that of photoluminescent analysis.