Sputtered copper oxide (CuO) thin films for gas sensor devices

Copper oxide (CuO) thin films were deposited using a reactive DC sputtering method for gas sensor applications. The structure of the films determined by means of an x-ray diffraction method indicates that the phase of copper oxide can be synthesized in the total pressure and temperature ranges of 6–8.5 mbar and 151–192 °C, respectively. The resistivity of the film synthesized at a substrate temperature of 192 °C increases from 0.104 to 0.51 Ω m after absorbing CO 2 gas at 135 °C. The gas sensitivity of the film synthesized at the substrate temperature of 192 °C increases up to 5.1 in the presence of CO 2 gas at 160 °C. The gas sensitivity in the presence of N 2 gas reaches only 1.43 even at 200 °C.