Quinoidal Porphyrinoids as High-Performance Electron Acceptors for Organic Solar Cells: Design, Photophysics, and...

Quinoidal porphyrinoids represent a promising class of electron accepting materials due to their extended π conjugation, strong electron affinity, and structural rigidity, yet their application in organic solar cells (OSCs) remains unexplored. This work presents the design and synthesis of a nickel based quinoidal porphyrinoid (NiQP) and its implementation as an n type acceptor in bulk heterojunction OSCs using PM6 as the donor polymer. NiQP exhibits broad absorption extending into the near-infrared region and a narrow optical bandgap of approximately 1.44 eV, enabling complementary light harvesting with PM6. PM6:NiQP devices deliver a power conversion efficiency (PCE) of 8.47% in as cast films, which increases to 12.51% after solvent vapor annealing (SVA), mainly due to enhanced short circuit current density and fill factor. Photophysical and electrical analyses show that SVA improves nanoscale morphology, exciton diffusion, and dissociation efficiency, while suppressing bimolecular and trap assisted recombination. Energy loss analysis further indicates reduced radiative and non radiative recombination losses in SVA treated devices, accompanied by lower Urbach energy and diminished energetic disorder. These results demonstrate the potential of quinoidal porphyrinoids as efficient electron acceptors and provide guidelines for molecular design and processing strategies in next generation OSCs.