Synergy of Plasmonic Silver Nanorod and Water for Enhanced Planar Perovskite Photovoltaic Devices

Perovskite solar cells (PSCs) have been widely studied during the past 10 years. Albeit the excellent light-absorption ability, the thickness of the perovskite layer is limited to maintain effective control over morphology and carrier migration. Meanwhile, the quality of perovskite films is a crucial factor affecting the performance of final devices. The traditional one-step process for preparing triple-cation perovskite films suffers from small grain size, low crystallization quality, and many surface defects. Herein, in the process of triple-cation perovskite-based solar cells, a facile dosing strategy of a silver nanorods (AgNR) aqueous solution into the perovskite precursor is adopted. The localized surface plasmon resonance effect of AgNR enhances the light-capture ability of the perovskite layer without increasing the thickness. At the same time, the presence of appropriate water helps to obtain high-quality perovskite films with larger grain size and fewer defects. It is found that the synergy of AgNR and water successfully reduces the defect density and increases mobility significantly. Consequently, a power conversion efficiency of 20.18% and a short-circuit current ( J SC ) of 22.08 mA cm −2 is achieved. Meanwhile, an excellent fill factor beyond 82% is reported, which is one of the highest values for triple-cation hybrid PSCs.