Structural and optical characterization of copper oxide composite thin films elaborated by GLAD technique

Abstract

In this work, Cu2O/CuO composite films were obtained by annealing, in free air, Cu thin films. These latter were deposited on glass substrates by Glancing Angle Deposition “GLAD” technique at a fixed glancing angle α, measured from the substrate normal. Nanorods tilted toward the incident deposition direction are produced with stationary substrate. Cu GLAD films were deposited under various angles α (0–80°). Structural and optical properties of obtained films were investigated based on XRD, Raman and UV–vis absorption data. The dependence of these properties on annealing temperature and deposition angle was analyzed. The obtained XRD patterns and Raman spectra revealed Cu2O, CuO and metallic Cu phases in films annealed at 200 °C, while a CuO monophase was obtained after annealing at 300 °C. Microstructural parameters, such as crystallite size, strain and dislocation density were calculated using Williamson–Hall model. Stacking fault probability was determined using Warren–Warekois relation. Band gap and Urbach energies, as well as other optical parameters were estimated from optical absorption data. The obtained results are in good agreement with the literature.