Pulsed laser deposition of Y3Al5O12:Tb photoluminescent thin films

Transparent-photoluminescent Y3Al5O12:Tb (YAG:Tb) thin films were deposited on single-crystalline sapphire at two different substrate temperatures by means of the pulsed laser deposition technique. The ablation targets were fabricated from YAG:Tb powders obtained with a new ceramic processing technique (combustion synthesis). A KrF excimer laser with an ultraviolet wavelength of 248 nm was used to evaporate the target and to grow the films. Analysis and characterization of the films were performed by scanning electron microscopy, x-ray diffraction, Auger electron spectroscopy, and photoluminescence measurements. As-deposited films were amorphous and deficient in oxygen as compared to the target. Additionally, these films were not luminescent. Postannealing treatments in air for at least 1 hr in the range 800-1200 degrees C were found to be necessary in order to induce crystallization and oxygenation in the films thus recovering the green photoemission of YAG:Tb with these treatments. (C) 1996 American Vacuum Society.