Luminescence properties of nanocrystalline YVO4:Eu3+ under UV and VUV excitation

Single phase of Eu3+-doped YVO4 nanophosphors at different pH values were synthesized by a mild hydrothermal method. Their photoluminescence were evaluated under UV and VUV region, respectively. Monitoring by 619 nm emission, broad bands at around 143 nm, 200 nm, 260 nm were observed in the excitation spectrum of YVO4:5 mol%Eu3+. These peaks could be assigned to host absorption, the overlap of the VO43− host absorption and charge transfer transition between Eu3+ and O2−, respectively. Both 254 nm and 147 nm excitations, the emission spectra were identical, they were all composed of Eu3+ emission transitions arising mainly from the 5D0 level to the 7FJ (J = 1, 2, 3, 4) manifolds. With the pH values ranging from 7 to 11, the relative intensity of the emission spectra were decreasing, and the position of the predominant peak (5D0 → 7F2) was changed from 619 nm to 615 nm when the pH values changed from 7 to 11.