  Interface engineering is one of the promising strategies for the long-term
stabilization of perovskite solar cells, preventing chemical decomposition
induced by external agents and promoting fast charge transfer. Recently,
MXenes-2D structured transition metal carbides and nitrides with various
functionalization (=O,-F,-OH) demonstrated high potential for mastering the
work function in halide perovskite absorbers and significantly improved the
n-type charge collection in solar cells. This work demonstrates that MXenes
allow for efficient stabilization of perovskite solar cells besides improving
their performances. We introduce a new mixed composite bathocuproine:MXene,
i.e., (BCP:MXene) interlayer at the interface between an electron-transport
layer (ETL) and a metal cathode in the p-in device structure. Our investigation
demonstrates that the use of BCP:MXene interlayer slightly increases the power
conversation efficiency (PCE) for PSCs (from 16.5 for reference to 17.5%) but
dramatically improves the out of Glove-Box stability. Under ISOS-L-2 light
soaking stress at 63$\pm$ 1.5{\textdegree}C, The T80 (time needed to reduce
efficiency down to 80% of the initial one) period increased from 460 h to >
2300 h.

Materials Science