A novel SiO2–ZnS-Am-TiO2/PbS–CdS@ZnO-NRs/FTO photoanode based quantum dots sensitized solar cell

Abstract

In this study, a novel and cost-effective design of a solar cell was introduced that utilized array of Zinc Oxide (ZnO) nanorods sensitized with Lead Sulfide (PbS) and Cadmium Sulfide (CdS) quantum dots (QDs). Three devices of the proposed solar cell architecture were fabricated using Fluorine-doped Tin Oxide (FTO) coated glass as a substrate and varying numbers of successive ionic layer adsorption and reaction (SILAR) cycles (10, 15, and 20) for PbS/CdS QDs sensitization. Three additional layers (Amorphous TiO2, ZnS, SiO2) were added to prevent charge recombination and ensure efficient charge transfer. The ZnO nanorods were formed and confirmed by scanning electron microscopy (SEM) analysis, which revealed that the relatively dense packing density of nanorods provided an adequate surface area for attachment of the PbS/CdS QDs. The optical properties of the solar cells were studied using UV–Visible spectroscopy, which showed that the optical absorption increased with an increase in the number of SILAR cycles. The proposed solar cell architecture exhibited a remarkable power conversion efficiency of 5.12%, which was attributed to the synergistic effects of the ZnO nanorods and PbS/CdS QDs. The unique design of solar cells with additional passivation layers makes it highly efficient, cost-effective, and easy to fabricate. Moreover, the use of readily available materials and the simplicity of the fabrication process make it a promising candidate for large-scale photovoltaic applications. Maximum efficiency of 5.12% was obtained. The finding of this study confirms that the proposed novel architecture can be a promising solar cell.