Plasmonic enhancement for high efficient and stable perovskite solar cells by employing "hot spots" Au nanobipyramids

Abstract

Metal plasmonic effect is one promising way for improving the performance and stability of the perovskite solar cells via optical-electrical behalves, and the ability is in proportion to the enhanced local electromagnetic fields induced by metal nanostructures. In our work, unique gold nanobipyramids (Au NBs) structures were explored and incorporated in the hole transport layer of planar heterojunction PSCs. This typical "bipyramid-like" metal nanostructure with sharp tips has the multiple and strong plasmonic absorption properties from visible to the NIR, exhibiting high plasmonic-induced probability. In addition, generated "hot spots" around Au NBs provided much stronger EM fields enhancements than conventional Au nanoparticles, hence enhanced light harvesting and improved interfacial charge dynamic process can be achieved simultaneously. As for the further investigation of the electrical property, hot holes injection induced by Au NBs effectively filled in the interfacial traps under operation condition, contributing to the improvement of the open circuit voltage, the elimination of the hysteresis effect and the long-term stability. Accordingly, the best PSC incorporated with Au NBs showed the PCE of 18.84% whereas the reference device just showed the PCE of 16.02%. Our work demonstrated that plasmonic metal nanostructures possessing the feature of "hot spots" offered a great potential to further expand the performance limitation and operation tolerance of the PSCs.