Physical properties of Y2O3:Eu luminescent films grown by MOCVD and laser ablation

Luminescent Y2O3:Eu3+ thin films were deposited on sapphire, polycrystalline Al2O3 and indium tin oxide coated glass or sapphire substrates by two different techniques: metallorganic chemical vapor deposition (MOCVD) and laser ablation. Microcrystalline Y2O3:Eu films were grown in a MOCVD chamber by decomposing and reacting yttrium and europium organometallic precursors in an oxygen atmosphere at low pressures (1-10 mTorr) and low substrate temperatures (500-700 degrees C). The as-deposited films showed the characteristic red fluorescence spectrum of Y2O3:Eu with the main peak centered about 611 nm wavelength. The as-deposited films averaged 1.0 mu m in particle size and 2.0 mu m in thickness. Post-deposition annealing treatments in the temperature range 900-1200 degrees C enhanced the luminescent intensity of the films. The as-deposited laser ablated oxide films were amorphous and required annealing at temperatures higher than 800 degrees C to observe luminescence, which occurred in conjunction with crystallization. The as-deposited films averaged 500 nm in thickness and after post-annealing at 1000 degrees C were composed of 15-200 nm grains.