Optical properties of sol–gel derived Y2O3:Eu3+ thin-film phosphors for display applications

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 °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 photoluminescence properties of these Y2O3:Eu3+ thin films depend principally on the film thickness and annealing temperature. The Y2O3:Eu3+ thin film annealed at 1200 °C had a thickness of ∼ 1.7 μm and exhibited a CL luminance of ∼ 150 cd/m2 and Commission International del'Eclairage coordinates of (0.64, 0.35) under 5 kV e-beam excitation at 5 μA/cm2. 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.