Room temperature-deposited silver oxide (AgxO) films by dc magnetron sputtering with high sputtering power density: Impact of flow rate ratio of O2 to Ar gases on microstructure pattern, optical and electrical behaviors

Abstract

Highly crystallized silver oxide (AgxO) films have been room-temperature deposited on glass substrates by direct-current (dc) magnetron sputtering with high sputtering power density. The impact of flow rate ratio of O2 to Ar gases (O2/Ar) is in particular studied on the microstructure pattern, optical and electrical behaviors of the AgxO films especially pure AgO films. An evolution in phase clearly occurs with increase of O2/Ar. The absorption edge in unit eV of the AgxO film composed of AgO and Ag2O, and the pure AgO films slightly varies near 2.7 eV with O2/Ar. The pure AgO films are best crystallized at 2:1 O2/Ar, and overdose of O worsens the crystallization of the AgO films, due to the lattice distortion mainly arising from Ag vacancies and interstitial O. The free carrier concentration and resistivity of fully oxidized AgxO film and AgO films are reduced and then increased with increase of O2/Ar. Cubic phases Ag2O and AgO are both p-type conductive, mainly due to the O vacancies, and Ag vacancies and interstitial O, respectively. The pure AgO films have high carrier mobility that is strongly affected by the point defects including vacancies and interstitial atoms.