Electric Field Distribution Engineering at the Buried Interface for High‐Performance Inverted Perovskite Solar Cells

ABSTRACT Self‐assembled monolayers (SAMs) have bridged the efficiency gap between p‐i‐n and n‐i‐p perovskite solar cells (PSCs), achieving power conversion efficiencies (PCEs) exceeding 28%. However, energy level misalignment caused by iodine vacancy‐induced n‐type doping between the perovskite and the SAM layer interface still leads to significant non‐radiative recombination losses. To address this, we designed and synthesized a novel co‐adsorbent material, (2E,2 'E ,2 ''E )‐3,3 ' ,3 '' ‐(nitrilotris(benzene‐4,1‐diyl))tris(2‐cyanoacrylic acid) (CA), featuring strong electron‐withdrawing capability. When combined with (4‐(3,6‐dimethyl‐9 H ‐carbazol‐9‐yl)butyl)phosphonic acid (Me‐4PACz), CA effectively reconstructs the electric field distribution at the buried interface. The incorporation of CA not only increases the work function of Me‐4PACz to optimize energy level alignment but also substantially improves the interfacial electric field characteristics. Consequently, the unfavorable depletion region for hole transporting process has been significantly reduced with the introduction of CA. The resulting PSCs achieve a champion PCE of 26.52% with enhanced stability, retaining 95% of their initial efficiency after 2160 h of storage in N 2 atmosphere.