Multifunctional nanostructured host-guest POM@MOF with lead sequestration capability induced stable and efficient perovskite solar cells

Long term stability and the toxicity of leaked lead ions represent the main barriers for commercialization of perovskite solar cells (PSCs). Here we report a novel chemical doping strategy with a series of polyoxometalates-metal organic frameworks (P@Ms) host-guest nanostructured dopants, shattering those barriers while maintaining a high-power conversion efficiency (PCE). The controllably oxidation of Spiro-OMeTAD was achieved under an inert environment through regulating the mass loading of H 3 PMo 12 O 40 in a porphyrin-based MOF-545. Furthermore, the doped devices show a high PCE (21.5%) with remarkable long-term air stability, retaining approximately 85% of the initial PCE value for over 1000 h in ambient conditions. Significantly, the functionalized P@M with active sites as an encapsulation layer effectively restrict the migration and leakage of Pb 2+ from the degraded PSCs, preventing the possible heavy metal pollution. This efficient strategy addresses the main troublesome long-term stability and lead ions leakage issues simultaneously, yielding stable and environmental-friendly sustainable PSCs. Nanostructured Host-Guest POM@MOF was constructed and applied for chemical doping hole transport layer to address the stability and lead contamination issues in PSCs. The resulting POM@MOF doped PSCs achieved high efficiency of 21.53% with a substantially enhanced operational stability (> 1000 h) without encapsulation. Meanwhile, the functionalized POM@MOF could capture Pb 2+ leaked from degraded PSCs, reducing impact on the environment. • A novel chemical doping strategy with nanostructured host-guest POM@MOF was proposed. • P@M-x achieve controllable oxidation of Spiro-OMeTAD under the inert condition. • The doping of nanostructure enhances the moisture and operating stability of PSCs. • HTM with functionalized P@M as encapsulation layer sequester 70% of leaked Pb 2+ .