Chemically Synthesized ZnO-WO3 Nanoparticles as Electron and Hole Transport Layer in Organic Solar Cells

Abstract

In this study, ZnO-WO3 nanoparticles are prepared by sol-gel technique. Various characterization techniques have been utilized for studying morphological, optical, as well as structural properties of the synthesized nanostructures. Two sets of inverted organic solar cells have been constructed by the chemically synthesized ZnO-WO3 nanoparticles as electron transport layer (ETL) and as hole transport layer (HTL) and the solar cell characteristics were examined. The first solar cell (device A) employing ZnO-WO3 as ETL was fabricated with configuration ITO/ZnO/ZnO-WO3/PTB7-Th:PC71BM/MoO3/Ag, while the other solar cell (device B) employing ZnO-WO3 as HTL was fabricated with structure ITO/ZnO/PTB7-Th:PC71BM/ZnO-WO3/MoO3/Ag. In comparison to the device A with ZnO-WO3 as ETL, a remarkable improvement is seen in device B with ZnO-WO3 as HTL. An efficiency of 1.88% is observed in device B in comparison to the efficiency of 0.64% in device A. The results suggest that ZnO-WO3 nanoparticles have great potential in photovoltaics.