Stability of reactively sputtered silver oxide films

Silver oxide films were deposited on glass substrates by RF magnetron sputtering of a silver target in various Ar–O2 reactive mixtures. At low oxygen flow rate, the films were biphased (Ag+Ag2O) while single Ag2O films were synthesised at higher oxygen flow rate. Films coming from the same deposition run were annealed in air at 200 and 300 °C. Whatever, the deposition conditions and the annealing temperature, Ag2O grains were either partially or fully decomposed into metallic silver and oxygen. Furthermore, the intensity of the Ag2O diffraction peaks decreased when a bias voltage was applied to the substrate holder. These results showed that the Ag2O phase is not stable during a thermal treatment or when submitted to an ion bombardment.