Preparation of Y2O3:Eu3+ nanopowders via polymer complex solution method and luminescence properties of the sintered ceramics

Herein we presented polymer complex solution method for production of well crystalline europium doped Y2O3 nanopowders. Polyethylene glycol (PEG) of five different molecular weights is used both as a fuel and as a nucleation agent for the crystallization. Powders were cold-pressed and sintered to obtain ceramics. SEM images taken from ceramic pellets indicate formation of a dense structure, with a pronounced grain growth and low pore concentration. Luminescence emission spectra of powders and ceramics are similar, and in good agreement with theoretical data. Lifetimes of Eu3+ 5D0 level in nanocrystalline powders are higher compared to one observed in bulk, confirming in this case theory of lifetime lengthening in nanophosphors due to the change of effective refraction index. As expected, lifetime values in ceramic samples decrease toward the value in bulk Y2O3. The optical filling factor is calculated from observed decay times, providing a measure of discrepancy between powder and bulk state regarding their luminescent properties.