Two-Dimensional Metal-Organic Frameworks as Charge Extraction Media Enabling Binary Organic Solar Cells With 20.70% Efficiency

Metal-organic frameworks (MOFs), recognized for their tunable, highly conjugated frameworks and exceptional charge-transport properties, exhibit significant potential in organic solar cells (OSCs). However, their integration has been hampered by inadequate dispersibility in low-polarity solvents. Herein, the two-dimensional MOF materials, Cu-TCPP and Zn-TCPP, were synthesized and precisely infiltrated into the upper region of the active layer through an anti-solvent strategy, which significantly enhanced charge transport through continuous π-d conjugation within the MOF layers. Moreover, intermolecular interactions between MOFs and acceptor L8-BO, including metal-center coordination and π-π effect enabled by conjugated porphyrin ligands, facilitate superior molecular packing, a double-fibril structure, and favorable vertical phase separation. Consequently, Zn-TCPP-incorporated D18:L8-BO OSCs achieve an outstanding efficiency of 20.70%, ranking among the highest reported values for binary devices. Meanwhile, the anchoring effect of MOFs significantly enhances the morphological stability of the active layer, endowing the OSCs with over twofold improvement in operational stability. This work not only opens a novel pathway for integrating high-performance MOF materials into OSCs but also establishes a promising paradigm for constructing efficient charge transport channels and fabricating highly stable, high-performance organic photovoltaics.