High Efficiency Semiconductor‐Liquid Junction Solar Cells based on Cu/Cu₂O

Cu/Cu 2 O photoelectrodes are synthesized by a simple electrodepositing process at low temperature. The values of the electrolyte pH have great influence on the morphology and the compositions of the obtained films, and thus affect the performance of the electrodes. The best device based on Cu/Cu 2 O and I − /I 3 − electrolyte gives a high conversion efficiency of 3.13% under simulated AM1.5G illumination. To the best of our knowledge, this is the highest efficiency reported for solar cells based on electrodeposited Cu 2 O. For comparison purposes, pure Cu 2 O films are also synthesized. The performance of the solar cells based on pure Cu 2 O is very poor, as low as 0.013%. In addition, the Cu/Cu 2 O films are perfectly compatible with the lightweight plastic substrates and yielded a power conversion efficiency of 1.44%.