Electrical and optical properties of copper oxide thin films prepared by DC magnetron sputtering

Copper oxides (CuO, Cu2O) have promising application potential in sensors or solar cells. In this study, copper oxide thin films were prepared by reactive DC magnetron sputtering using helicon plasma. A pure copper target was sputtered with Ar gas in an O2 atmosphere with a DC sputtering power in the range of 10–40 W, while the other fabrication conditions were kept constant. X-ray diffraction and x-ray photoelectron spectroscopy were used to investigate the effect of the sputtering power on the structure and the chemical state of the fabricated films. Atomic force microscopy was used to determine the relationship between the film's surface morphology and its structure. Hall effect measurements were employed to measure the semiconductor's properties, and the optical bandgap was determined by UV-Vis spectroscopy. The copper oxide film could be continuously tuned from n-type CuO to p-type Cu2O by changing the DC magnetron sputtering power.