Twisted Nanoribbon-Like Electron Acceptor With Suppressed Non-Radiative Loss and Seed-Assisted Crystallization for...

While large π-conjugated nanoribbons possess highly tunable electronic properties, their potential in high-performance organic photovoltaics (OPVs) remains largely untapped. Herein, we report a π-extended nanoribbon-like electron acceptor, PDIY, featuring a molecular length of 4.85 nm (11 fused rings) and near-infrared absorption extending to 900 nm. PDIY is engineered with a perylene diimide core fused to dual rylene units and end-capped with Y-type acceptor moieties. The rigid conjugated framework effectively suppresses conformational/vibronic relaxation, weakens electron-phonon coupling, and yields an intrinsically low non-radiative voltage loss (ΔV_nr) of 0.146 eV, among the lowest values reported to date, thereby enabling higher open-circuit voltage. Despite its large size, the twisted geometry of PDIY leads to a unique "low crystallinity, strong aggregation" behavior. This allows PDIY to serve as a potent morphology-directing additive that acts in a manner consistent with heterogeneous nucleation, inducing the formation of robust, large-diameter fibrillar networks within bulk-heterojunction blends. Consequently, the integration of PDIY yields a simultaneous enhancement across all photovoltaic parameters, boosting power conversion efficiencies (PCEs) from 19.62% to 20.57%. This work establishes twisted nanoribbon-like acceptor as a versatile molecular platform for the dual regulation of excited-state dynamics and active-layer morphology in next-generation OSCs.