INFLUENCE OF CATIONIC PRECURSOR CONCENTRATION ON THE OPTICAL AND STRUCTURAL PROPERTIES OF COPPER OXIDE THIN FILMS DEPOSITED BY CHEMICAL BATH DEPOSITION TECHNIQUE

Abstract

Copper oxide thin films were fabricated on glass substrates using the chemical bath deposition method with a deposition time of 20 minutes. The structural and optical properties of the films were investigated using X-ray diffraction (XRD) and optical analyses, focusing on the effects of varying copper acetate((CH3 .COO)2 Cu·H2 O ) as the Cu precursor concentrations., hydrazine (N2 H5 OH) as a complexion agent, and ammonium hydroxide (NH4 OH) as a pH regulator at a bath temperature of 80°C. The films were deposited by adding 1ml, 2ml, 3ml, 4ml, and 5 ml of 0.4 M copper acetate to the bath solution. The films were smooth, well-adherent, uniform, and thick. The films were characterized by X-ray diffraction for structural study and UV-VIS spectrophotometer for the study of optical properties. The XRD study revealed that the films deposited with 1 to 3 ml of copper acetate solution crystallized in the monoclinic phase of the CuO structure, with two prominent peaks at 35.5° and 38.7°, which are indexed to the (002) and (111) planes of the monoclinic CuO structure. The films deposited with 4 and 5 ml of copper acetate had an additional peak at 36.5°, which is indexed to the (111) plane of cubic Cu2 O. Optical studies revealed that the CuO thin films have a direct band transition with values of 2 eV, 1.85 eV, 1.8 eV, 1.95 eV, and 2.2eV for CuO thin films deposited with 1 ml, 2 ml, 3 ml, 4 ml, and 5 ml of copper acetate, respectively