Structural and luminescent characteristics of pulsed laser deposited Eu³⁺-doped Y₂O₃thin films

Thin films of Eu-doped Y2O3 were deposited using the pulsed laser ablation technique on amorphous fused silica substrates. The effect of oxygen partial pressure (pO2) and substrate temperature on the structural and optical characteristics of the deposited films were investigated. All the deposited films were crystalline, showing preferred orientation along the (111) plane, irrespective of oxygen partial pressure and substrate temperature. The film deposited at 0.005 mbar pO2 exhibited better crystallinity with minimum FWHM at a substrate temperature of 600°C. All the films deposited at various substrate temperatures and different partial pressure (at 600°C) exhibited a red luminescence peak at 615 nm corresponding to the 5D0–7F1 transition in Eu3+. Photoluminescence excitation spectra exhibited two bands, one corresponding to band to band excitation (212 nm) of the host and the other to charge transfer band excitation (245 nm). A microstructure analysis revealed that surface roughness of the as-deposited films increases with increase in oxygen partial pressure.