Plasmonic Au Nanooctahedrons Enhance Light Harvesting and Photocarrier Extraction in Perovskite Solar Cell

Improvements in the light-harvesting capacity and the carrier extraction are both significant to improve the photovoltaic performance of perovskite solar cells (PSCs). It has been proved that local surface plasmon resonance (LSPR) based on metallic nanostructures is practical for capturing light to enhance light harvesting. Motivated by this, a special shaped Au nanoparticle, e.g., nanooctahedrons (Au NOs), with a broadband LSPR peak and a suitable size is controlled synthesized and applied in a PSCs device. The power conversion efficiency of PSCs is increased from 16.95 to 19.05% with a short-circuit current density (Jsc) as high as 23.63 mA/cm2. Besides the enhanced light-trapping effect of Au NOs LSPR proved by optical spectroscopy analysis, the Kelvin probe force microscopy results show that Au NOs can also effectively reduce the surface potential of the electron transport layer, which promotes effective photocarrier extraction at the interfaces. This paper sheds light on the question of how plasmon excitation and light localization might be used advantageously in high-efficiency photovoltaics.