Supramolecular Cavity Confinement Inducing Ordered C₆₀ Assembly and Suppressed Interfacial Non-Radiative Recombination for Efficient and Scalable Perovskite Solar Cells

Charge-carrier non-radiative recombination at the perovskite/C₆₀ interface seriously limits the device efficiency and operational stability. Herein, we report a cavity-confined and directionally assembled strategy by introducing 4-tert-butylcalix[6]arene (4tBu-C[6]A) at the perovskite/C₆₀ interface, which facilitates uniform and compact C₆₀ deposition via size matching and host–guest interactions. The calixarene-cavity enables strong π–π stacking with C₆₀, which is further enhanced by the electron-donating tert-butyl groups, thus firmly immobilizing and improving the dispersion of C₆₀. Moreover, the lower-rim hydroxyl groups in 4tBu-C[6]A interact with the under-coordinated Pb²⁺ and couple with the 1,3-propyldiammonium diiodide interfacial molecules, strengthening the field-effect interfacial passivation, accelerating electron transport, and enhancing the quasi-Fermi level splitting. This supramolecular template strategy enables a minimal non-radiative voltage loss of 68 mV. Consequently, the inverted perovskite devices achieve power conversion efficiencies of 26.68%, 25.13%, and 23.07% on active areas of 0.09, 1, and 12.96 cm², respectively. Additionally, the target devices retain over 80% of their initial efficiencies after 1100 h of maximum power point tracking. This work provides a scalable interfacial engineering strategy for perovskite photovoltaics and highlights the potential of supramolecular chemistry in functional optoelectronic interfaces.