Photoluminescence properties of nanocrystalline Tb3+ doped Y2O3 phosphor prepared through a novel synthetic route

Green emitting cubic Y2O3:Tb3+ nanocrystalline phosphor having particle size of 22 nm was synthesized by TEA (triethanolamine) based precursor solution method. We have characterized our nanocrystalline sample by XRD, HRTEM and Raman spectroscopic measurement. We compared the photoluminescence properties of our nanocrystalline sample with the bulk one. Due to the presence of defect states and lower phonon density of nanomaterials, cross relaxation process seems to be less effective in nanosized sample reflecting higher blue/green ratio in nanosized sample. Relative intensity of 5D4–7F5 transition with respect to 5D4–7F6 transition is reduced in nanosized sample due to greater transition probability of the latter transition in the distorted nanostructured material. Our analysis suggests that change of local environments takes place with decreasing the particle size and it is reflected in the photoluminescence spectra.