The
nonradiative carrier recombination at the perovskite/carrier
selective layer (CSL) interface was accounted for the inferior power
conversion efficiency (PCE) of perovskite solar cells (PSCs), especially
rigid all-inorganic perovskite (CsPbI3 and CsPbBr3). In this study, targeting the poor interface, we introduce SbX3 (X = Cl, Br, I) surface passivation at the CsPbBr3/carbon interface. Smoothed compressive strain, reduced defect density,
and enhanced energy-level alignment were achieved simultaneously,
facilitating carrier extraction at the selective interface. With the
simple aqueous solution-based two-step process, the PCE of our SbI3 passivated carbon-based CsPbBr3 PSCs has increased
from 7.81% (without passivation) to 9.69%, a ∼25% enhancement.
Specifically, V
oc (1.657 V) of the SbI3-passivated cells was much higher than that of the control
ones (1.488 V), confirming the ameliorated interface. Finally, our
unencapsulated SbI3 passivated devices maintain 90% of
their initial PCEs while left in the air for 30 days with a relative
humidity of 60%. To conclude, we present an interfacial carrier extraction-enhanced
strategy for preparing high-performance and stable CsPbBr3-based PSCs.