Long wavelength optical absorption and photovoltaic performance enhancement on CuInS2 and PbS quantum dot co-sensitized solar cells

CuInS2 and PbS quantum dots (QDs) are prepared by successive ionic layer adsorption and reaction (SILAR) process for photo-anode of quantum dot sensitized solar cells (QDSSCs). And the optical properties and photovoltaic performance of CuInS2 and PbS QDSSCs with different structure are investigated. The absorption intensity is obviously enhanced and absorption edge is expanded to the near-infrared region for the TiO2/PbS/CuInS2 QDSSCs. The TiO2/3PbS/4CuInS2 QDSSCs have the great photovoltaic conversion efficiency of 2.93%, which is attributed to the better photocurrent response at long wavelength region and band energy level matching of CuInS2 and PbS QDs to improve charge generation and transfer performance.