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Abstract Wearable devices benefit from the use of stretchable conjugated polymers (CPs). Traditionally, the design of stretchable CPs is based on the assumption that a low elastic modulus (E) is crucial for achieving high stretchability. However, this research, which analyzes the mechanical properties of 65 CP thin films, challenges this notion. It is discovered that softness alone does not determine stretchability; rather, it is the degree of entanglement that is critical. This means that rigid CPs can also exhibit high stretchability, contradicting conventional wisdom. To inverstigate further, the mechanical behavior, electrical properties, and deformation mechanism of two model CPs: a glassy poly(3‐butylthiophene‐2,5‐diyl) (P3BT) with anEof 2.2 GPa and a viscoelastic poly(3‐octylthiophene‐2,5‐diyl) (P3OT) with anEof 86 MPa, are studied. Ex situ transmission X‐ray scattering and polarized UV–vis spectroscopy revealed that only the initial strain (i.e., <20%) exhibits different chain alignment mechanisms between two polymers, while both rigid and soft P3ATs showed similarly behavior at larger strains. By challenging the conventional design metric of lowEfor high stretchability and highlighting the importance of entanglement, it is hoped to broaden the range of CPs available for use in wearable devices. 

Abstract Space missions critically rely on sensors that operate throughout the near‐ to longwave infrared (NIR – LWIR, λ = 0.9–14 µm) regions of the electromagnetic spectrum. These sensors capture data beyond the capabilities of traditional optical tools and sensors, critical for the detection of thermal emissions, conducting atmospheric studies, and surveillance. However, conventional NIR‐LWIR detectors depend on bulky, cryogenically cooled semiconductors, making them impractical for broader space‐based applications due to their high cost, size, weight, and power (C‐SWaP) demands. Here, an IR photodetector using a solution‐processed narrow bandgap conjugated polymer is demonstrated. This direct bandgap photoconductor demonstrates exceptional infrared sensitivity without cooling and has minimal changes in figures‐of‐merit after substantial ionizing radiation exposure up to 1,000 krad – equivalent to three years in the most intense low Earth orbit (LEO). Its performance and resilience to radiation notably surpass conventional inorganic detectors, with a 7.7 and 98‐fold increase in radiation hardness when compared to epitaxial mercury cadmium telluride (HgCdTe) and indium gallium arsenide (InGaAs) photodiodes, respectively, offering a more affordable, compact, and energy‐efficient alternative. This class of organic semiconductors provides a new frontier for C‐SWaP optimized IR space sensing technologies, enabling the development of new spacecraft and missions with enhanced observational capabilities. 

Abstract Photodetectors operating across the near‐ to short‐wave infrared (NIR–SWIR,λ= 0.9–1.8 µm) underpin modern science, technology, and society. Organic photodiodes (OPDs) based on bulk‐heterojunction (BHJ) active layers overcome critical manufacturing and operating drawbacks inherent to crystalline inorganic semiconductors, offering the potential for low‐cost, uncooled, mechanically compliant, and ubiquitous infrared technologies. A constraining feature of these narrow bandgap materials systems is the high noise current under an applied bias, resulting in specific detectivities (D^*, the figure of merit for detector sensitivity) that are too low for practical utilization. Here, this study demonstrates that incorporating wide‐bandgap insulating polymers within the BHJ suppresses noise by diluting the transport and trapping sites as determined using capacitance‐frequency analysis. The resultingD^*of NIR–SWIR OPDs operating from 600–1400 nm under an applied bias of −2 V is improved by two orders of magnitude, from 10⁸to 10¹⁰ Jones (cm Hz^1/2 W⁻¹), when incorporating polysulfone within the blends. This broadly applicable strategy can reduce noise in IR‐OPDs enabling their practical operation and the realization of emerging technologies.