Polymer-capped copper nanoparticles trigger plasmonic field for improving performance of perovskite solar cells

Abstract Plasmonic nanostructures are often incorporated into perovskite solar cells (PeSCs) to achieve high power conversion efficiencies (PCEs) while using thin perovskite films and/or minimum amount of photoactive materials. Most plasmonic nanostructures, however, are based on noble metals, including gold and silver. High material cost somehow limits commercial applications in these cost-effective solar modules. In this work, we use copper (Cu), which is a more abundant and low-cost element, to prepare plasmonic nanoparticles (NPs); they also exhibit well plasmonic properties in the visible wavelength region. To overcome the instability of the Cu NPs, the NPs are further capped with polyvinylpyrrolidone (PVP) to avoid oxidation under ordinary ambient conditions. After the PVP-capped Cu NPs are incorporated into PeSCs, the devices exhibit improved PCEs under illumination at 1 sun; we attribute the device enhancement to local plasmonic field enhancement induced by the Cu NPs. Additionally, the PeSCs prepared with polymer-capped Cu NPs possess reasonable stability. We anticipate that the results in this study might open up new opportunities for fabricating plasmon-enhancing solar modules using cost-effective Cu nanostructures.