Improved cathodoluminescent characteristics of Y2O3:Eu3+ thin films by Li-doping

Y2O3 : Eu3+ luminescent thin films have been studied as a potential red phosphor thin film for application in field emission display. Y2(O3): Eu3+ and Li-doped Y2O3: Eu3+ films have been grown on Al2O3(0001) substrates using a pulsed laser deposition technique at substrate temperature of 600 degrees C under the various oxygen pressures. The cathodoluminescent intensity of the Y2O3: Eu3+ films were highly dependent not only on the crystallinity, but also on the surface roughness of the films. Cathodoluminescent spectra for both Y2O3: Eu3+ and Li-doped Y2O3: Eu3+ films were dominated by the red emission peak at 612 nm radiated by the transition of D-5(0)-F-7(2) within europium and the brightness of the Li-doped films was increased by a factor of 1.4 in comparison with that of the Y2O3: Eu3+ films. It is understood that Li ions affect the luminescence of the Y2O3: Eu3+ films by influencing its crystallinity and surface roughness. The cathodoluminescent intensity and surface roughness had similar behavior as a function of oxygen pressure.