Effect of dopant concentration on photoluminescence properties of Dy3+ doped Gd2O3 nanophosphors under different excitation wavelengths

Abstract

In this work, the role of dopant Dy3+ concentration and excitation wavelength on luminescence properties of Dy3+ doped Gd2O3 nanophosphors prepared by chemical precipitation method were studied. The phosphors were characterized by X-ray diffraction (XRD), Energy dispersive analysis of X-ray (EDAX) and photoluminescence spectroscopy. The crystallite sizes of the phosphors were found to be in the range of 11–17 nm. The profile of the emission spectra for the phosphors was independent of dopant concentration as well as excitation wavelengths. The photoluminescence emission peaks were observed at 486 nm and 574 nm corresponding to 4F9/2-6H15/2 and 4F9/2-6H13/2 transitions respectively. The optimum concentration of Dy3+ for maximum emission intensity was found to be 2 at.% of Dy3+ which was independent of excitation wavelength. The emission intensity of all prepared phosphors under 234 nm excitation wavelength was found to be stronger than that of 278 nm. This showed the energy transfer due to host absorption was more efficient. The color emission of different concentration of Dy3+ doped Gd2O3 nanophosphors under different excitation wavelengths were studied from calculated CIE coordinates and was found to be shifted towards the blue region with the increase of dopant concentration.