Hybrid copper–indium disulfide/polypyrrole photovoltaic structures prepared by electrodeposition

Photovoltaic structures on the basis of photoactive polycrystalline CuInS₂ (CIS) in combination with electrically conductive polymer polypyrrole (PPy) were prepared using the electrodeposition technique. In order to prepare stable PPy films with a good adherence to the surface of CIS, the appropriate concentrations of reagents, current densities and electrodeposition potentials were selected experimentally. Electrochemical polymerization of pyrrole to PPy on the CIS surface is faster under white light irradiation, and the polymerization starts at a lower potential than in the dark. Significant photovoltage and photocurrent of the fabricated CIS/PPy structures have been observed under standard white light illumination. The best structure showed an open-circuit voltage of 509 mV, a short-circuit current density of 6.45 mA/cm², fill-factor 0.47 and photoconversion efficiency of 1.53% under white light illumination of 100 mW/cm².