Characterization of CuTe nanofilms grown by underpotential deposition based on an electrochemical codeposition technique

This study reports the synthesis of semiconductor CuTe nanofilms using underpotential deposition (UPD) technique based on the simultaneous, constant-potential electrochemical codeposition of Cu and Te from solution containing Cu2+ and HTeO2 (+). The electrochemical behaviors of copper, telluride, and Cu-Te system in the UPD and bulk regions were investigated. The synthesized CuTe nanofilms were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, and Raman spectroscopy. SEM analysis revealed that the CuTe films exhibited a nanoscale and quite uniform structure. The stoichiometric ratio of the Cu and Te was determined to be 1:1 by XPS. XRD results showed that the CuTe films exhibit an orthorhombic structure, are polycrystalline. The band gaps of CuTe were observed to range from 2.68 to 3.70 eV depending on the deposition time and deposition potential. Bands were observed at 164, 231, and 264 cm(-1) in the Raman spectra of the CuTe nanofilms.