Rare earth doped α-alumina thin films prepared by pulsed laser deposition:: structural and optical properties

alpha-Al2O3 films doped with about 1% Eu3+ were grown on sapphire (012) substrates by pulsed laser deposition using an ArF excimer laser under 10(-4) mbar oxygen pressure and at temperatures higher than 1050 degreesC. The Eu doping rate was measured by Rutherford backscattering spectroscopy. The crystalline structure was determined by X-ray diffraction and transmission electron microscopy. The films are grown epitaxially on the sapphire substrate. The Eu3+ fluorescence spectra are constituted of narrow lines. By means of pulsed laser deposition, Eu3+ ions may be introduced into a single site of the alpha-phase lattice, with a concentration that cannot be reached using conventional crystal-growth methods.