Covalent Organic Framework-Templated Molecular Contacts for Inverted Perovskite Solar Cells

Abstract

Self-assembled molecule-based hole-selective contacts are critical for high-efficiency inverted perovskite solar cells (PeSCs), yet conventional self-assembled monolayers (SAMs) suffer from poor wettability and interfacial energy losses. Here, we integrate SAMs with imine-linked covalent organic frameworks (ILCOFs) to construct an ILCOF/SAM-intercalated hole-selective layer (HSL) featuring superwetting properties and improved morphology. The ILCOF nanosheets act as structural regulators, guiding SAM organization and promoting the growth of high-quality perovskite films with reduced interfacial defects. This hierarchical contact also enhances energy-level alignment and interfacial coupling, reducing voltage loss and improving thermal stability. As a result, PeSCs incorporating ILCOF/SAM deliver a power conversion efficiency of 26.06% and exhibit negligible performance degradation over 2,020 h of continuous operation. Furthermore, this strategy is compatible with scalable fabrication, yielding mini-modules with 22.95% efficiency over a 12.5 cm2 aperture area.