Preparation Nanostructured of Cu-Doped NiO Thin Films Using Spin Coating Method for Gas Sensors Applications

In this paper, copper doped nickel oxide as the thin films have been synthesized by a sol-gel spin coating method for gas sensing application. The ratios of Cu –doped were (1, 2, and 3) %wt. The characterization of obtained films was investigated in detail of the structural, morphological surface, optical properties, and sensing properties of Nitrogen dioxide (NO2) and hydrogen sulfide (H2S) gases. The crystallinity was confirmed by the x-ray diffraction (XRD) analyses. The surface morphology is characterized by atomic force microscopy (AFM). The NiO: Cu films have a polycrystalline with a cubic structure phase. The results of AFM showed the roughness and grain size distribution decreased from (13.56-22.71) nm, and (2.56-5.21) nm, respectively. The optical property showed that the highest absorption of the obtained films was 0.739 to the 1%Cu sample and the bandgap decreased from (3.31 to 3.01) eV with increasing Cu doped. The results of sensing analysis showed the doping of NiO film with Cu was suitable for gas sensing applications where the electrical conductivity of NiO was an enhancement.