Optical and Electrical Properties of CuO Thin Films by Spray Pyrolysis Method

Thin films (300 nm thick) of CuO of p-type conductivity were precipitated using the spray pyrolysis method from 0.2 M of aqueous CuCl2 · 2 H2O salt solution on preheated (up to 350°C) glass and sitall substrates. The structure and electrical and optical properties of the films are analyzed. The grain size of CuO thin films (24 nm) was calculated using the XRD analysis. The activation energy equals Ea = 0.27 eV, which may indicate that the conduction is due to the transition of charge carriers from the valence band to the working acceptor level. From the spectral dependence (αhν)2 = f(hν) of CuO thin films, the band gap width Eg = 1.46 eV was determined.