CuO-Ga2O3 Thin Films as a Gas-Sensitive Material for Acetone Detection.

The p-n heterostructures of CuO-Ga2O3 obtained by magnetron sputtering technology in a fully reactive mode (deposition in pure oxygen) were tested under exposure to low acetone concentrations. After deposition, the films were annealed at previously confirmed conditions (400 °C/4 h/synthetic air) and further investigated by utilization of X-ray diffraction (XRD), X-ray reflectivity (XRR), energy-dispersive X-ray spectroscopy (EDS). The gas-sensing behavior was tested in the air/acetone atmosphere in the range of 0.1-1.25 ppm, as well as at various relative humidity (RH) levels (10-85%). The highest responses were obtained for samples based on the CuO-Ga2O3 (4% at. Ga).