Structural and luminescent characteristics of pulsed laser deposited Eu³⁺-doped Y₂O₃ thin films

Abstract

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.

Keywords:

• yttria thin film
• pulsed laser ablation
• photoluminescence

Acknowledgements

This work was supported by Department of Science and Technology, Govt. of India. The author G.A. wishes to thank the Centre for Excellence in Lasers and Optoelectronic Sciences for the grant of a fellowship.