Pulsed voltage deposited hierarchical dendritic PbS film as a highly efficient and stable counter electrode for quantum-dot-sensitized solar cells

Abstract

Hierarchical dendritic PbS films were deposited on fluorine doped tin oxide (FTO) glass substrates as counter electrodes (CE) for quantum dot-sensitized solar cells (QDSSCs) by a facile one-step pulse voltage electrodeposition method. The electrodeposition time was the key factor to obtain the hierarchical dendritic PbS films. The morphology and the structure of the as-prepared films under different electrodeposition times were investigated by XRD, SEM, TEM and EDS. The results showed that perfect hierarchical dendritic PbS films could be obtained at an electrodeposition time of 20 s. The electrocatalytic and photovoltaic properties of these films as CEs for QDSSCs were evaluated by electrochemical impedance spectroscopy (EIS), Tafel polarization measurements, CV cycling and J–V curves. The hierarchical dendritic PbS exhibits superior catalytic activity and stability in the polysulfide electrolyte, and significantly improved the performance of CdS/CdSe co-sensitized solar cells. An optimized power conversion efficiency (PCE) of 5.76% was achieved, and the QDSSCs were stable for over 24 h. The present study provides a simple pathway to obtain an efficient CE for the QDSSCs.