Three different benzylammonium halide (Cl, Br, and I) salts were investigated to elucidate their effects as additives on MAPbI3 perovskite surface morphology, crystal structure, optical properties, and solar cell performance and stability.
The passivation of surface defects at the interfaces and grain boundaries of perovskites has great potential to improve the optoelectronic properties of related devices. In this study, the small molecules LG0.5, LG1.5, and LG2.5—having precise and controllable molecular weights (various generations synthesized through click reactions) and featuring urethane, urea, and malonamide functionalities—are synthesized, and their ability to passivate the defects of perovskites are evaluated. X‐ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and time‐resolved photoluminescence spectroscopy are used to observe the interactions between the perovskites and these molecules. The embedding of LG0.5 promotes the growth of large‐grain perovskite crystals, leading to increases in the intensities of the UV–vis absorption and photoluminescence spectral signals of the perovskite as well as longer carrier lifetimes. A power conversion efficiency of almost 20% for a p‐i‐n perovskite solar cell having the layer structure indium tin oxide/NiOx/CH3NH3PbI3 (with LG0.5)/[6,6]‐phenyl C61 butyric acid methyl ester/bathocuproine/Ag is observed. This device (without encapsulation) exhibits excellent air‐stability, retaining 89.8% of its initial performance after storage in an ambient environment (25 °C, 40% humidity) for over 120 d.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.