Semiconducting Covalent Organic Frameworks as Functional Dopants for Efficient Perovskite Solar Cells

ABSTRACT This study presents the first comprehensive investigation of pyrene‐based covalent organic frameworks (COFs) as bulk dopants in formamidinium lead iodide (FAPbI ₃ ) perovskite solar cells (PSCs). A series of three frameworks—sp ² c‐PyCOF, Im‐PyCOF, and SH‐PyCOF—were synthesized to systematically evaluate the effects of distinct linkage chemistries and Lewis‐basic functionalities (–C≡N, –C = N–, and –SH) on perovskite optoelectronic performance. When incorporated into the perovskite precursor solution, the PyCOFs coordinate with undercoordinated Pb ^{2 +} sites, effectively passivating deep trap states and suppressing non‐radiative recombination. Their extended π‐conjugation further promotes efficient charge delocalization and transfer within the bulk perovskite. Consequently, PyCOF‐doped PSCs demonstrated enhanced charge extraction and higher Fill Factors, achieving champion power conversion efficiencies of ∼19.5%, outperforming both undoped devices (17.75%) and pyrene‐free COF controls. These findings establish π‐conjugated pyrene COFs as a new class of multifunctional dopants that couple structural stability with optoelectronic tunability, offering a rational molecular design platform for the next‐generation of high‐performance and durable perovskite photovoltaics.