Production of Cu2O[copper (I) oxide]thin films by electrochemical technique and investigation of properties

In this work, p-type semiconductor Cu2O films were electrodeposited on ITO substrate, from a solution with a pH value of 10 and a temperature of 500C. The deposition potentials were determined as -260, -320, 400 and -480 mV from cyclic voltammograms. The thickness of the films were 500, 1000 and 2000 nm. Nucleation and growth mode of the films were studied by current density-time. The crystal structure properties were determined by X-ray diffraction technique. All deposited films have characteristic reflections of cubic crystal of Cu2O, which are (110), (111), (200), (220), (311), (222). d-spacing, grain size, lattices parameter and texture coefficient were calculated. The d-spacing and the lattices parameter are compatible with the theoretical values. According to the texture coefficients, at -260 mV, the films with the thicknesses of 500 nm and 2000 nm have (110) preferential orientation, and the thickness of 1000 nm has (200) preferential orientation. At -320 mV, the films with the thicknesses of 500 nm and 1000 nm have (110) preferential orientation and the thickness of 2000 nm has (111) preferential orientation. All films deposited at -400 and -480 mV have (111) preferential orientation Mott-Schottky measurements revealed that all films are p-type semiconductor. For -260 mV, the flat band potential decreases with the increasing the thickness. For -480 mV, there is not any regular change. From the electrochemical impedance spectroscopy the solution resistance, the charge transfer resistance and diffusion angle were determined. The morphology was investigated by scanning electron microscopy (SEM). Cu2O films have spheres on the surface. As the thickness increases, the size of the spheres and the distance between the spheres increase. Key words: : Cu2O, electrodeposition, thin film, oxide semiconductor