FAPbBr3 perovskite solar cells with VOC values over 1.5 V by controlled crystal growth using tetramethylenesulfoxide†
Perovskite solar cells (PSCs) capable of an open-circuit voltage (VOC) of over 1.5 V were fabricated based on a formamidinium lead-bromide (FAPbBr3) perovskite absorber film prepared by a sequential deposition procedure using a dimethylsulfoxide (DMSO) and tetramethylenesulfoxide (TMSO) mixed solvent. A PbBr2 film formed from a precursor PbBr2 solution with the DMSO–TMSO mixed solvent was reacted with FABr to conversion into an FAPbBr3 film. The mixed solvent-based PbBr2 film exhibited an amorphous-like phase containing a PbBr2–TMSO complex, which led to the formation of an FAPbBr3 film possessing high crystallinity and a uniform thick absorber layer compared with the pristine PbBr2 film prepared with pure DMSO solvent. With a bandgap of 2.1 eV, FAPbBr3-based PSCs prepared via the solution process with the PbBr2–TMSO complex exhibited a high VOC value of up to 1.55 V and a power conversion efficiency of 7.8% on device fabrication using an Li-treated mesoporous TiO2 as an electron transport layer with a 5 × 5 mm2 cell active area.
- This article is part of the themed collection: Journal of Materials Chemistry A HOT Papers