Performances Enhancement in Perovskite Solar Cells by Incorporating Plasmonic Au NRs@SiO2 at Absorber/HTL Interface

Metallic nanoparticles (NPs) exhibit a surface plasmon resonance (SPR) and can be incorporated into perovskite solar cells (PSCs) to improve cell performance. However, the incorporation of Au NPs in bulk films of PSCs requires large concentration to keep interval distance and would cause worse device performance. In this work, a universal strategy for significant increasing power conversion efficiency (PCE) of PSCs through incorporating high aspect ratio Au nanorods (NRs)@SiO 2 into perovskite/spiro‐OMeTAD interface is demonstrated. The key feature of this approach is that we can take advantage of the SPR at a lower concentration and the Au NRs have larger light scattering section than AuNPs. It is found that the SPR and scattering effect of Au NRs lead to a broad enhancement of photon absorption. Furthermore, a superior enhanced charge separation process in the Au NRs incorporated device is also observed. Benefitting from this cooperative plasmonic effect of Au NRs in optical and electrical aspects, both short‐circuit current density and open‐circuit voltage are improved, resulting in the new device delivering a PCE up to 17.39% from 14.39%. This result further supports that Au NRs can play a more effective SPR effect at perovskite/spiro‐OMeTAD interface, rather than incorporating them into bulk films.