Graded Supramolecular Frameworks for Extending Space‐Charge Modulation Regions and Boosting Carrier Dynamics in Perovskite Solar Cells

Abstract

ABSTRACT Efficient carrier separation and transport in perovskite solar cells are fundamentally constrained by the narrow space‐charge regions intrinsic to conventional device architectures, leaving thick perovskite bulks electrically inactive. Here, we report a supramolecular graded electrostatic potential modulation strategy enabled by a fluorine‐functionalized porous aromatic framework (PAF‐2F) that spatially redistributes space charge throughout the perovskite absorber. The graded incorporation of PAF‐2F continuously modulates the local electronic structure throughout the perovskite bulk, establishing an extended electrostatic potential gradient and transforming carrier transport from diffusion‐dominated motion into field‐assisted drift. This extended internal field accelerates charge separation, suppresses nonradiative recombination, and enhances charge extraction, yielding a champion power conversion efficiency of 26.66%. Moreover, the rigid conjugated framework and strong interfacial interactions of PAF‐2F stabilize the graded doping profile and inhibit ion migration, resulting in excellent operational stability with 93% efficiency retention after 1000 h of continuous illumination without encapsulation. This work presents a general supramolecular strategy for bulk electronic structure engineering in perovskite semiconductors, offering a viable pathway toward simultaneously achieving high efficiency and long‐term stability.