LAUSR

In this study, cuprous oxide (Cu2O) nanostructures were deposited via electrochemical route from aqueous solution containing different concentrations of copper chloride (CuCl2). The effect of chloride (Cl− ) ions on structural and optical properties was studied. Photocurrent results show that the type of conduction of these nanostructures is affected by adding Cl− ions and changed from p-type to n-type conduction. The x-ray diffraction (XRD) shows that our samples were pure Cu2O with a preferential orientation along the (111) direction. The intensity of (111) peak increases with the increase of Cl− concentration. The optical characterization of Cu2O was studied by analyzing the transmission spectrum measured in normal incidence in the range of 300–1100 nm. The thickness and the refractive index of Cu2O nanostructures were determined using different methods. The optical gap energy (Eg) and associated Urbach energy (Eu) were also calculated. Effectively, the optical gap was estimated from Tauc extrapolation; it was found that it decreases from 2.02 eV to 1.85 eV with the increase in CuCl2 concentration; on the other hand, the thickness of the layers increases from 267 nm to 300 nm.