Role of Zn dopants on the surface morphology, chemical structure and DC electrical transport properties of nanostructured p-type CuO thin films

Abstract

This paper is based on the studies of surface morphology, chemical structure and DC electrical transport properties of zinc (Zn) doped copper oxide (CuO:Zn) thin films synthesized by spray pyrolysis technique. CuO and CuO:Zn thin films were deposited onto ultrasonically cleaned microscope glass substrates at the substrate temperature 623 K. Zn concentration (conc.) in CuO:Zn thin films was varied from 1 to 6 at%. In field emission scanning electron microscopic images of CuO:Zn thin films nanostructures are observed around the nucleation center. The maximum average particle size is found about 18 nm for 5 at% Zn doped CuO:Zn thin film. X-ray photoelectron spectroscopy confirms the chemical structure and composition of the films. Activation energy of CuO:Zn thin films in the temperature range 350–423 K increases from 0.17 to- 0.39 eV with the rise of Zn conc. In the range of 2–6 at%. DC electrical resistivity of CuO:Zn thin films is found in the order of 104 Ω-cm. Hall effect measurements confirms the p-type conductivity of CuO:Zn thin films with the carrier conc. In the order of 1018 cm-3. Carrier mobility of 5 at% CuO:Zn thin film is as high as 84.83 cm2 V-1 s-1.