LAUSR

Abstract Quasi two-dimensional (Quasi-2D) layered perovskites show higher stability with respect to three-dimensional (3D) perovskites. And compared with two-dimensional (2D) perovskites, quasi-2D perovskites exhibit an improvement in power conversion efficiency (PCE) of perovskite solar cells (PSCs) due to reduced exciton binding energy. So far, different strategies have been adopted to increase PCEs of the quasi-2D PSCs by forming high crystalline quasi-2D perovskite films. In this work, we show that the performance of the quasi-2D aromatic phenylethylammonium based PSCs can be improved greatly through interfacial engineering, i.e., by introducing a layer of SiO 2 coated AuAg-alloyed nanoprisms (AuAgNPrisms@SiO 2 ) before coating the active layer. As a result, the short circuit current density and PCE increased by 32.8% and 34.1%, respectively. Morphological studies show that the incorporated AuAgNPrisms@SiO 2 particles can serve as inducers for forming highly smooth quasi-2D perovskite film. Comprehensive studies indicate that AuAgNPrisms@SiO 2 can also reduce the series resistance, increase light absorption, induce the photon recycling scheme, and assist exciton dissociation at the interface. The combination of all these helpful effects contributes to the observed PCE improvement of quasi-2D PSCs. Our results provide novel insight into the effect of metallic nanoparticles on the quasi-2D perovskite film and on the performance of quasi-2D PSCs.