High-quality Cu2O thin films via electrochemical synthesis under a variable applied potential

In this work, highly Cu2O film purity have been synthesized via electrodeposition technique by means of a variable applied potential [cyclic voltammetry (CV), linear sweep voltammetry (LSV) and - 0.5 V]. This paper highlights the effect of using variable potential approaches during the film preparation on the properties of Cu2O-deposited films. The prepared films were analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV-Vis absorption and photoelectrochemical (PEC) analysis. XRD revealed that samples are crystallized in Cu2O cubic structure with a crystalline orientation in the plane (111) and a clear improvement of the crystallinity and size crystallite of the Cu2O deposited using CV process. SEM micrographs showed that the morphology grains were three-sided pyramid-shaped, expanding with increase of the crystallinity. The calculated band gap values are 2.18, 2.23 and 2.20 eV, respectively for - 0.5 V, LSV, CV. The Cu2O films synthetized in this study showed high PEC activity with very low carrier density in comparison with the conventionally electrodeposited films.