Strain‐Induced Detectivity Enhancement in Intrinsically Stretchable Organic Photodetectors

ABSTRACT Intrinsically stretchable organic photodetectors (IS‐OPDs) are essential for next‐generation wearable electronics requiring both mechanical durability and reliable optical sensing. However, current performance of IS‐OPDs degrades under tensile strain due to inherent trade‐offs between mechanical and optoelectronic properties in photoactive layers. Here, we report the development of the IS‐OPD that exhibits strain‐induced detectivity ( D ) enhancement, enabled by designing mechanically robust and efficient bilayer‐type photoactive architecture (EBL‐D). Specifically, we incorporate percolated polymer donor ( P D ):elastomer networks at the bottom layer, which simultaneously offer excellent stretchability and efficient charge transport. Subsequently, we deposit a small‐molecule acceptor layer atop the P D :elastomer layer, expanding the optical absorption range into the near‐infrared region while minimizing undesirable charge recombination. The resulting IS‐OPD based on the EBL‐D architecture maintains high responsivity and effectively suppresses dark current under strain. Consequently, the device exhibits 1.5‐fold improvement in specific detectivity from 1.9 × 10 13 to 2.8 × 10 13 Jones at λ = 860 nm under 75% strain, corresponding to a 1.3‐fold increase in D after accounting for the enlarged photoactive area. To the best of our knowledge, this work is the first to experimentally demonstrate strain‐induced D enhancement in stretchable OPDs.