Effect of Deposition Potential on Synthesis, Structural, Morphological and Photoconductivity Response of Cu2O Thin Films by Electrodeposition Technique

Abstract

The present work describes the effect of deposition potentials on structural, morphological, optical, electrical and photoconductivity responses of cuprous oxide (Cu2O) thin films deposited on fluorine-doped tin oxide glass substrate by employing electrodeposition technique. X-ray diffraction patterns reveal that the deposited films have a cubic structure grown along the preferential (111) growth orientation and crystallinity of the film deposited at − 0.4 V is improved compared to the films deposited at − 0.2, − 0.3 and − 0.5 V. Scanning electron microscopy displays that surface morphology of Cu2O film has a well-defined three-sided pyramid-shaped grains which are uniformly distributed over the surface of the substrates and are significantly changed as a function of deposition potential. Raman and photoluminescence spectra manifest that the film deposited at − 0.4 V has a good crystal quality with higher acceptor concentration compared to other films. UV–visible analysis illustrates that the absorption of Cu2O thin film deposited at − 0.4 V is notably higher compared to other films and the band gap of Cu2O thin films decreases from 2.1 to 2.04 eV with an increase in deposition potential from − 0.2 to − 0.5 V. The frequency–temperature dependence of impedance analysis shows that the film deposited at − 0.4 V has a high conductivity. I–V measurements elucidate that the film deposited at − 0.4 V exhibits a good photoconductivity response compared to films deposited in other deposition potentials.