Preparation of copper oxide thin film by the sol–gel-like dip technique and study of their structural and optical properties

Copper oxide films are prepared using a methanolic solution of cupric chloride (CuCl2 · 2H2O) by the sol–gel-like dip technique at different baking temperatures. XRD study confirms that the films are of Cu2O phase when prepared at a baking temperature of 360°C and CuO phase when prepared at 400–500°C baking temperature. The optical direct band gap energies for Cu2O and CuO films calculated from optical absorption measurements are 2.10 and 1.90 eV, respectively, which are quite comparable with the reported values.