Enhancement of photoelectrochemical solar cell performance by surface modification of Cu₂O using Hg heteroepitaxial growth

Abstract

Cupric oxide (Cu₂O) thin films have been synthesized on copper (Cu) substrates using thermal oxidation method. The heteroepitaxial growth Hg/Cu₂O/Hg thin films were successfully grown on Cu₂Oprepared with soaring stability and superiority in various compositions by an economic, simple and reliable microwave oven method using Bromine powder as transporting agent. The influence of the substrate and heteroepitaxial growth on the structural properties of copper II oxide films was discussed. The formations of Cu₂O thin films are further identified by Fourier transform infrared spectroscopy. PEC performances of the Hg/Cu₂O electrodes containing different peak structures were determined, and the changes of PEC activities were examined comparatively. The photovoltaic properties demonstrated by the sample have been found to act as photocathodes and they have p-type conductivity. The synthesized PEC solar cells under illumination of Cu-Hg/Cu₂O/Hg and Cu-Cu₂O results in the short circuit current density (ISC) of 50.0 and 0.14mA, power conversion efficiency (PCE) of 0.50and 0.036%, and open-circuit voltage (V_oc) of 18 and 11.0mV respectively. Our findings reveal that the PCE of Hg/Cu₂O/Hg heteroepitaxial growth thin-film PEC solar cell is enhanced through the usage of Hg as absorber layer in comparison to the Cu₂O stratum.