Terminal Fluorination Modulates Crystallinity and Aggregation of Fully Non‐Fused Ring Electron Acceptors for High‐Performance and Durable Near‐Infrared Organic Photodetectors

Abstract High dark current density ( J d ) severely hinders further advancement of near‐infrared organic photodetectors (NIR OPDs). Herein, we tackle this grand challenge by regulating molecular crystallinity and aggregation of fully non‐fused ring electron acceptors (FNREAs). TBT‐V‐F, which features fluorinated terminals, notably demonstrates crystalline intensification and a higher prevalence predominance of J‐aggregation compared to its chlorinated counterpart (TBT‐V‐Cl). The amalgamation of advantages confers TBT‐V‐F‐based OPDs with lower nonradiative energy loss, improved charge transport, decreased energetic disorder, and reduced trap density. Consequently, the corresponding self‐powered OPDs exhibit a 40‐fold decrease in J d , a remarkable increase in detectivity ( D * sh ), faster response time, and superior thermal stability compared to TBT‐V‐Cl‐based OPDs. Further interfacial optimization results in an ultra‐low J d of 7.30×10 ‐12 A cm −2 with D * sh over 10 13 Jones in 320–920 nm wavelength and a climax of 2.2×10 14 Jones at 800 nm for the TBT‐V‐F‐based OPDs, representing one of the best results reported to date. This work paves a compelling material‐based strategy to suppress J d for highly sensitive NIR OPDs, while also illustrates the viability of FNREAs in construction of stable and affordable NIR OPDs for real‐world applications.