Structural, optical and electrical properties of reactively sputtered Ag2Cu2O3 films

Ag2Cu2O3 thin films were deposited on glass substrates by RF magnetron sputtering of an equiatomic silver–copper target (Ag0.5Cu0.5) in reactive Ar–O2 mixtures. The reactive sputtering was done at varying power, oxygen flow rate and deposition temperature to study the influence of these parameters on the deposition of Ag2Cu2O3 films. The film structure was determined by X-ray diffraction, while the optical properties were examined by spectrophotometry (UV–vis-NIR) and photoluminescence. Furthermore, the film thickness and resistivity were measured by tactile profilometry and 4-point probe, respectively. Additional mobility, resistivity and charge carrier density Hall effect measurements were done on a few selected samples. The best films in terms of stoichiometry and crystallography were achieved with a sputtering power of 100 W, oxygen and argon flow rates of 20 sccm (giving a deposition pressure of 1.21 Pa) and a deposition temperature of 250 °C. The optical transmittance and photoluminescence spectra of films deposited with these parameters indicate several band gaps, most prominently, a direct one of around 2.2 eV. Electrical characterization reveals charge carrier concentrations and mobilities in the range of 1021–1022 cm− 3 and 0.01–0.1 cm2/Vs, respectively.