摘要： Recently, perovskite solar cells (PSCs) attracted phenomenal research interest owing to their potential as the next-generation photovoltaics. Despite rapid development in this field, increasing their power conversion efficiency (PCE) remains a critical issue for the commercialization of PSCs. In this work, we have investigated the application of Ag nanoparticle (NPs) layers via vapour-phase deposition onto perovskite active layers. The formation of unique, crescents shaped Ag NPs is confirmed by scanning electron microscopy (SEM), which shows that the NPs self-assemble along the grain boundaries of perovskite leading to their unique shape. The PCE for devices incorporating an optimized size of Ag NPs of 79 ± 6 nm increased from 11.63% to 13.46% with the improvement factor of 15.74%. The increase in PCE mainly attributed to the increase in short circuit current (Jsc) that is assigned to an increase in optical path length and absorption. As NPs possess the ability to increase the optical path length of photons in the device due to the near field and far-field enhancement (plasmonic scattering) and consequently may act to improve the photon to electron conversion efficiency (ΔIPCE) and PCE of PSCs. Moreover, ultraviolet photoelectron spectroscopy revealed a decrease in hole injection barrier (?h) also contributed to enhanced performance.