Sol-gel synthesis and physical properties of CuO:La nanocomposite thin films

CuO and CuO: La nanocomposite thin films have been deposited by the sol-gel process using the spin coating technique. Lanthanum at two different concentrations was introduced in thin layers having a thickness corresponding to three layers. The structural characterization by XRD reveals that the deposited CuO and La doped CuO thin films are monoclinic and cubic crystals structures successively, and also notes the presence of lanthanum copper oxide (La2CuO4) which proves the insertion of dopant in the matrix, and the crystallite size of the films pure was affected by La concentration and was found to be decreased with the increase of La concentration. Raman measurement of CuO pure and CuO: La nanocomposite thin films confirmed the structure of CuO and Cu2O. SEM studies revealed a uniform and relatively dense surface with small pyramids enveloping the nanometric-sized crystallite. It was found that the value of the optical energy gap increases with increasing of La for all samples.