Nanocrystalline CuO Thin Films for H 2 S Monitoring: Microstructural and Optoelectronic Characterization

Abstract

Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, morphological , optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H 2 S sensors. The dependence of the H 2 S response on the operating temperature, H 2 S concentration of CuO film (annealed at 700˚C) was investigated. The CuO film showed selectivity for H 2 S. The maximum H 2 S response of 25.2% for the CuO film at gas concentration of 100 ppm at operating temperature 200˚C was achieved.