Polyfluorinated‐Regulator‐Assisted Scaffold‐Directed Tilted 1D/3D Heterointerfaces for High‐Voltage and Stable Perovskite Solar Cells

Abstract

ABSTRACT Protective low‐dimensional interphases can improve perovskite solar‐cell stability, but they often compromise charge extraction because of unfavorable interfacial packing and transport barriers. Herein, we report a scaffold‐directed strategy to construct an interwoven tilted 1D/3D heterointerface on inverted perovskite absorbers. By depositing PbI 2 onto a tilt‐oriented 3D perovskite scaffold and inducing solvent‐assisted reconstruction, a compact near‐surface interphase composed of edge‐sharing 1D PbI 2 and face‐sharing 1D δ ‐FAPbI 3 is formed with an oblique orientation guided by the crystallographic texture of the underlying 3D framework. Unlike conventional laterally aligned low‐dimensional overlayers, this tilted 1D interphase preserves out‐of‐plane interfacial connectivity while providing a robust barrier against defect propagation and ion migration. We further identify 7F‐EA‐HI, a flexible polyfluorinated ammonium iodide, as an effective crystallization regulator that suppresses reconstruction‐induced defects and favorably modulates interfacial energetics through its large molecular dipole. As a result, the optimized inverted PSCs deliver a power conversion efficiency (PCE) of 24.94%, with an open‐circuit voltage ( V OC ) of 1.188 V, a short‐circuit current density ( J SC ) of 24.67 mA cm −2 , and a fill factor (FF) of 85.11%, along with markedly improved ambient and thermal stability. This work demonstrates tilted 1D/3D interfacial engineering as a viable route toward high‐voltage and durable perovskite optoelectronics.