Laser Manufactured Nano-MXenes with Tailored Halogen Terminations Enable Interfacial Ionic Stabilization of High Performance Perovskite Solar Cells

摘要

Formamidinium (FA)-based perovskite promises high power conversionefficiency in photovoltaics while it faces awkward spontaneous yellowphase transition even at ambient conditions. This has spurred intensiveefforts which leave a formidable challenge on robust anchoring of the softperovskite lattice. Present work pioneers the rational design of interfacialionic-bonding between halogen-terminated nano-MXenes and perovskitefor effective retarding of the lattice instability in FA-based perovskites. Therobust heterointerface between perovskite and nano-MXenes results also ineffectively modulating the deep-energy-level defects, lowering the interfacialcharge transfer barrier, and tuning the work function of perovskite films.Benefiting from these merits, unencapsulated FA-based perovskite solar cellsafter the ionic stabilization (champion efficiency up to 24.17%), maintain over90% of their initial efficiency after operation at maximum power point undercontinuous illumination for 1000 h, and retain more than 85% of their initialefficiency even after annealing for 1000 h at 85 ℃ in inert atmosphere.