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

Abstract

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  E_a = 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 E_g = 1.46 eV was determined.