A characterization on emission property of In2O3–SiO2 nanocomposite thin films

Nanocomposite thin films containing finely dispersed, crystalline In2O3 nanoparticles embedded in SiO2 matrix were fabricated by target-attachment sputtering method. Transmission electron microscopy observed single crystalline In2O3 nanoparticles uniformly embedded in SiO2 matrix of the samples with In2O3 content less than about 60 vol.%. Photoluminescence spectra of the In2O3–SiO2 nanocomposite samples were found to comprise of the blue, green and red emissions. Analytical results indicated that the red and green emissions are correlated to the transitions from conduction band (CB) edge to the Ini••• and V‴In defect levels, respectively, while the blue emission is originated from the transition from CB edge to VO•• level or from VO• level to the valence band edge.

► PL properties of In2O3–SiO2 nanocomposite layers were analyzed to explore the emission mechanism. ► Visible-light emissions were correlated to the defect level transitions in bandgap of In2O3. ► Red emission is correlated to the transitions from CB edge to Ini••• defect level. ► Green emission is originated from the transitions from CB edge to V‴In defect level. ► Blue emission resulted from the transition from CB edge to VO•• level or VO• level to VB edge.