Optical and electrical properties of CuO thin films deposited at several growth temperatures by reactive RF magnetron sputtering

Copper oxide thin films were deposited on glass substrates at various growth temperatures by the reactive radio-frequency magnetron sputtering method. The band gap energy, carrier concentration and figure of merit of the CuO thin films were found to depend significantly on the growth temperature. All of the CuO films, irrespective of growth temperature, showed a monoclinic structure with the main CuO orientation, and the crystallite size, determined by using Scherrer's formula, was about 50 nm for the thin film deposited at 25 A degrees C. The highest figure of merit occurred for the film grown at 300 A degrees C with an optical transmittance of 62.9% in the wavelength range of 800-1100 nm. The results suggest that the optimum growth temperature for growing high-quality CuO thin films is 300 A degrees C.