Development of Organic Semiconductor Photodetectors: From Mechanism to Applications

Photodetectors that convert a light signal into an electrical signal have wide applications in light signal detection. As an emerging candidate for next-generation light sensing, organic photodetectors compensate well for the shortages of the traditional inorganic photodetectors in terms of ease of processing, compatibility with flexible substrates, tunable absorption characteristics, low-cost manufacturing, and being lightweight. Currently, regular improvements in organic photodetectors are made with respect to their important figure-of-merit performances, which have caught up to or even surpassed the performances of inorganic Si and Ge-based photodetectors. Importantly, the spectral response of organic photodetectors covers a wide range of wavelengths, from the ultraviolet to near-infrared regions, with low-band-gap organic semiconductors as the active medium. In this paper, the working mechanism and recent advances in organic semiconductor photodetectors are comprehensively reviewed and the challenges in the field, mainly focusing on the performance of organic photodetectors, studies oriented toward applications, and the expectations of organic semiconductor photodetectors in the future, are disclosed.