Enhanced Performance and Stability of Planar Perovskite Solar Cells by Interfacial Engineering using Fluorinated Aliphatic Amines

Interface engineering is an effective way to improve perovskite solar cell (PSC) performance. In this work, we selected a series of fluorinated aliphatic amine hydroiodide to modify perovskite film in order to enhance its hydrophobicity and interface charge transport in PSC. In addition, fluorinated aliphatic amine hydroiodide treatment leads to large perovskite grains and decreases the number of grain boundaries, which benefits the durability and photoelectric transfer performance. Photoluminescence and electrochemical impedance spectroscopy results demonstrate that fluorinated aliphatic amine hydroiodide-modification suppresses charge carrier recombination and accelerates electron injection from perovskite to PCBM. Thus, the power conversion efficiency (PCE) of PSC based on fluorinated aliphatic amine hydroiodide-modified perovskite film increases from 12.23% to 13.88%. The PCE of a modified PSC without any encapsulation maintains about 85% after exposure to 50% humidity for 10 days because of the enhanced hydrophobicity of modified perovskite films.