Thin films of silver-copper-oxide were deposited on glass substrates by RF magnetron sputtering of Ag80Cu20 target under various oxygen partial pressures in the range 5 × 1 0 ？ 3 – 8 × 1 0 ？ 2 ？Pa. The effect of oxygen partial pressure on the crystallographic structure and surface morphology and electrical and optical properties was systematically studied and the results were reported. The oxygen content in the films was correlated with the oxygen partial pressure maintained during the growth of the films. The films which formed at low oxygen partial pressure of 5 × 1 0 ？ 3 ？Pa were mixed in phase of Ag2Cu2O3 and Ag while those deposited at 2 × 1 0 ？ 2 ？Pa were grown with Ag2Cu2O3 and Ag2Cu2O4 phases. The films which formed at oxygen partial pressure of 2 × 1 0 ？ 2 ？Pa showed electrical resistivity of 2.3？？cm and optical band gap of 1.47？eV. 1. Introduction The silver-copper-oxygen (Ag-Cu-O) system consists of various ternary compounds Ag2Cu2O3, Ag2Cu2O4, and AgCuO2. In 1999 the first ternary silver copper oxide compound, Ag2Cu2O3 was prepared by Gomez-Romero et al. [1] in powder form by using a coprecipitation method at room temperature. Later in the second ternary silver copper oxide compound, Ag2Cu2O4 was synthesized by electrochemical oxidation of suspension of the precursor Ag2Cu2O3 [2–5] at room temperature and ozone oxidation [6]. Curda et al. [7, 8] synthesized mixed silver copper monoxide, AgCuO2, which is diamagnetic and showed mixed valence again, with the formula of A g I C u I I O2. Most of the recent studies on silver copper oxides concentrated mainly on the determination of physical properties such as the crystal structure and thermal stability. There has been a shift towards looking at applications, with groups studying silver copper oxides as positive electrode in button cell batteries [9–12] or as new promising materials for photovoltaic applications. The silver copper oxides are p-type semiconductors, which could potentially be used as absorber material for future generation photovoltaic devices [13]. The ternary oxide of silver and copper also has novel applications in the fields of science and technology such as high Tc-super conductors [14]. Various thin films deposition techniques such as thermal oxidation of metallic films, pulsed laser deposition and sputtering were employed for the growth of metallic oxide films. Among these methods, magnetron sputtering technique is industrially practiced technique for the growth of thin films on larger area substrates. The physical properties of magnetron sputter deposited metal oxide films
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