Efficient plasmon-enhanced perovskite solar cells by molecularly isolated gold nanorods

Perovskite solar cells(PSCs)are becoming a promising candidate for next-generation photovoltaic cells due to their attractive power conversion efficiency(PCE).Plasmonic enhancement is regarded as an optical tuning approach for further improving the PCE of single-junction PSCs toward Shockley-Queisser limit.Herein,we introduce molecularly isolated gold nanorods(Au NRs),bearing relatively stronger scattering ability and localized surface plasmonic resonance(LSPR)effect,in the rear side of perovskites in PSCs,for promoting light harvesting and for electrical enhancement.Owing to the larger refractive index and better matched energy level alignment,the 4-mercaptobenzoic acid molecules coated on Au NRs prove to play important dual roles:isolating the metallic Au NRs from contacting with perovskite,and facilitating more efficient charge separation and transport across the interface under the synergetic LSPR effect of Au NRs.Our work highlights the capability of the plasmonic approach by nanorods and by molecular isolation,extending nanoparticle-based plasmonic approaches,toward highly efficient plasmon-enhanced PSCs.