A General Strategy for Enhancing Sensitivity and Suppressing Noise in Infrared Organic Photodetectors Using Non‐Conjugated Polymer Additives

Document Type


Publication Date



Polymer Science and Engineering


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 resulting D* of NIR–SWIR OPDs operating from 600–1400 nm under an applied bias of −2 V is improved by two orders of magnitude, from 108 to 1010 Jones (cm Hz1/2 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.

Publication Title

Advanced Functional Materials

Find in your library