Y2O3:Eu3+ thin-film phosphors were grown on sapphire substrates using a simple sol-gel process. The films were annealed at various temperatures between 700 and 1400 degrees C for 2 h in air after deposition. The optical properties, morphologies and crystallographic structures of the Y2O3:Eu3+ thin films are characterized and discussed. The sol-gel process enabled the synthesis of efficient Y2O3:Eu3+ thin-film phosphors with good optical properties, high crystallinities and smooth morphologies. The cathodoluminescence (CL) and photo luminescence properties of these Y2O3:Eu3+ thin films depend principally on the film thickness and annealing temperature. The Y2O3:Eu3+ thin film annealed at 1200 degrees C had a thickness of similar to 1.7 mu m and exhibited a CL luminance of similar to 150 cd/m(2) and Commission International del'Eclairage coordinates of (0.64, 0.35) under 5 kV e-beam excitation at 5 mu A/cm(2). A significant improvement (by a factor of about 2) was found in the aging characteristics of the Y2O3:Eu3+ thin-film phosphors under 5 kV CL excitation compared to those of powder phosphors. (c) 2006 Elsevier B.V. All rights reserved.