Lead sulfide films synthesized by microwave-assisted chemical bath deposition method as efficient counter electrodes for CdS/CdSe sensitized ZnO nanorod solar cells

Abstract In this study, PbS thin films are deposited on FTO substrate via a rapid and facile microwave-assisted chemical bath deposition (MACBD) and then used directly as the counter electrodes (CEs) for CdS/CdSe quantum dots co-sensitized ZnO nanorods array solar cells (QDSSC). The resultant PbS CEs show good uniformity, strong adhesion to the FTO and superior electrocatalytic activity for the reduction of polysulfide electrolyte compared to the PbS CEs prepared with conventional CBD method. The combination of ZnO/CdS/CdSe photoanode with the optimum PbS CE shows appreciated power conversion efficiency (PCE) of 4.85%. The augmented photovoltaic performance can be attributed to its high electrocatalytic activity for polysulfide reduction in QDSSC, which results in a low charge transfer resistance at the interface of CE/electrolyte. The results demonstrate the potential application of this MACBD method in fabricating efficient metal sulfide counter electrode for QDSSC.