CdO thin films: a study of their electronic structure by electron spin resonance spectroscopy

The Cd(C5F6HO2)2·polyether adducts were used in MOCVD experiments of cadmium oxide, on optical transparent SiO2 substrates. Very mild heating (44-74 °C) resulted in, thermal stable, liquid compounds that can be easily evaporated. XRD measurements provided evidence of cubic highly textured CdO(1 0 0) films. The surface atomic composition was investigated by XPS analysis. UV-vis spectra showed that the transmittance of as-deposited films in the visible region is about 90%. Resistivity measurements of CdO thin films showed that they are highly conducting. ESR analysis suggests the presence of Cd+ ions, on the site of Cd2+, arising from polaronic self-trapping of electrons introduced by oxygen deficiency at Cd2+ sites to generate localised 5s1 states.