Fabrication of homojunction Cu2O solar cells by electrochemical deposition

Homostructural Cu2O solar cells were fabricated with consecutive electrochemical depositions of a p-Cu2O thin film and a n-Cu2O layer on a transparent conductive substrate. The parameters of growth Coulomb number for n-type and p-type Cu2O films, which determine the film thickness of Cu2O, were fine-tuned to investigate their effects on the performance of homojunction solar cells. According to XRD and SEM analyses, the crystalline structure and the optimum thickness of Cu2O films were accomplished at growth Coulomb numbers 0.135 C for n-Cu2O and 0.208 C for p-Cu2O. Significantly, the best performance of the homojunction Cu2O cell achieved conversion efficiency 0.42% with Voc = 0.42 V, Jsc = 2.68 mA cm−2 and FF = 0.38. This work hence demonstrates that the proposed strategy to improve the performance of solar cells realized by electrochemical deposition has the potential to produce cheap and environmental friendly solar cells.