Vacuum-Evaporated Molecules with Giant Spontaneous Orientation Polarization for Inverted Perovskite Solar Cells

Abstract

Abstract Interfacial losses at the perovskite/C60 and C60/metal contacts limit inverted perovskite solar cell performance. Here, we introduce a vacuum-evaporated molecule with giant spontaneous orientation polarization, 6F-2PI, for simultaneously tailoring both interfaces. Incorporating 6F-2PI increases the work function of perovskite, reducing the conduction band offset at the perovskite/C60 interface, which facilitates electron extraction. Concurrently, its phthalimide moieties passivate defect states, suppressing nonradiative recombination, as evidenced by a 0.03 eV recovery in quasi-Fermi level splitting. At the C60/metal interface, 6F-2PI also delivers efficient charge extraction, improved interfacial contact, and thermal resilience. Moreover, its hydrophobic fluorinated units prevent moisture ingress. Consequently, this dual-interface modulation boosts PCE from 18.5% to 22.5% with exceptional device stability, retaining over 90% of its initial efficiency after 2000 h under ambient conditions. Furthermore, this framework exhibits universal compatibility across both vacuum-deposited and solution-processed devices and simplifies processing for mass production.