Synergistic Device Engineering Enables High‐Performance Intrinsically Stretchable Near‐Infrared Organic Photodetectors Under Strain up to 180%

ABSTRACT Intrinsically stretchable organic photodetectors (is‐OPDs) sensitive in the near‐infrared (NIR) region are promising for wearable health monitoring. However, maintaining optoelectrical properties while ensuring mechanical robustness under strain remains a challenge. This work demonstrates high‐performance NIR is‐OPDs by synergistically optimizing the optoelectronic and mechanical properties of transparent electrodes and photoactive layers. A DES (Choline Chloride:p‐Toluene Sulfonic Acid, ChCl:PTSA) modified PH1000 electrode improves the conductivity and stretchability owing to enhanced hydrogen bonding, charge delocalization, and increased carrier density. In addition, the soft elastomer poly(styrene‐butylene‐styrene) (SEBS) blended all‐polymer PM6:PY‐IT photoactive layer enhances stretchability without compromising low‐light detection. Is‐OPDs achieved a record detectivity of 9.2 × 10 11 Jones (corrected for noise current) in the NIR region at 180% tensile strain. After 120% mechanical deformation or 1000 stretching‐release cycles at 60% strain, these is‐OPDs can still detect the photoplethysmogram signal and blood oxygen precisely, which far exceeds the current applied mechanical stability of most is‐OPD devices.