Red light emission of Y2O3:Eu3+ nanophosphors and luminescent enhancement by the addition of gadolinium oxide as co-dopant

Abstract

This work presents the optical and structural properties of rare earth-doped and co-doped yttrium oxide nanophosphors. Europium oxide and gadolinium oxide-doped and co-doped Y2O3 phosphors were synthesized by make use of combustion method followed by annealing to different temperatures in order to obtain much more good crystallinity. The X-ray diffraction and Fourier transform infrared spectroscopy confirms the structural formation and phase purity of the compound. The diffuse reflectance spectra of doped and co-doped Y2O3 powder were analysed. It was found that there appears shifting of absorption edge towards longer wavelength region when compared to pure yttrium powder. The band gap was calculated by make use of Kubelka–Munk function. It was noticed that band gap increases with annealing temperature. The dependence of doping concentration, pH and annealing temperature on photoluminescence properties were studied in a systematic manner. The PL emission intensity was maximum for 6 wt% Eu3+-doped Y2O3 powders that results 5D0–7F2 transition within europium and emits red light at 612 nm under the excitation of 260 nm. In the case of co-dopant, maximum intensity is obtained for 7 wt% Gd3+ under the excitation of 255 nm.