The influence of several electrodeposition parameters such as concentration precursor, applied potential, pH, and temperature on phase composition, degree of crystallinity, grain size, and orientation have been studied by many researchers using electrodeposition technique for the elaboration of thin films. Some physical and chemical properties of materials depend strongly on the precursor type. Research to date has shown that the different precursors in bath deposition played an important role in the first stages of nucleation and growth of thin film. In this work, we have electrodeposited Cu₂O p-type semiconductor on FTO coated glass substrate at pH = 9.5 by using different copper precursor (CuSO₄, CuNO₃ and CuAc) with potentiostatic mode. The structural, and optical properties were characterized using X-ray diffraction (XRD), UV-Vis-NIR Spectroscopy and photoluminescence (PL) respectively. The MottSchottky (M-S) plot demonstrates that the type of the conductivity of the films depend on the nature and the concentration of the precursor, the flat-band potential and the acceptor density for the Cu₂O thin films are determined. The XRD measurements indicated that all the obtained films display a pure Cu₂O cubic phase. The optical transmission spectrum in the UV-Visible-NIR domains revealed a high transmission and the calculated gap values varied with the different precursor. PL spectra were taken to define the main radiative recombination paths. Besides the near band excitonic transitions, two strong emission bands associated with relaxed excitons at oxygen and copper vacancies were detected. Both excitonic-vacancy bond transitions presented similar intensities that are related to the growth method.

Key word: Electrodeposition, Mott-Schottky, Cu₂O, Nanostructure.