Dependence of photoluminescence (PL) emission intensity on Eu3+ and ZnO concentrations in Y2O3:Eu3+ and ZnO•Y2O3:Eu3+ nanophosphors

Y2O3:Eu3+ and ZnO center dot Y2O3:Eu3+ nanophosphor powders with different concentrations of Eu3+ ions were synthesized by a sol-gel method and their luminescence properties were investigated. The red photoluminescence (PL) from Eu3+ ions with the main emission peak at 612 nm was observed to increase with Eu3+ concentration from 0.25 to 0.75 mol% and decreased notably when the concentration was increased to 1 mol%. The decrease in the PL intensity at higher Eu3+ concentrations can be associated with concentration quenching effects. The red emission at 612 nm was shown to increase considerable when ZnO nanoparticles were incorporated in Y2O3:Eu3+ while green emission from ZnO was suppressed. The increase is attributed to energy transfer from ZnO to Eu3+. (C) 2011 Elsevier B.V. All rights reserved.