Biomimetic Flexible High-Sensitivity Near-Infrared II Organic Photodetector for Photon Detection and Imaging

The flexible near-infrared (NIR) organic photodetector is an essential prerequisite for the next-generation visual system for accurate information identification. However, prevailing limitations in NIR organic photodetectors, including high noise, weak responsivity, and low detectivity, directly impede the translation to practical applications. Herein, ultranarrow bandgap acceptors, featuring a 2D highly electron-donating central core (DTPC), named as YZ and YZ1, are designed and synthesized for NIR organic photodetectors. It is found that the introduction of highly rigid DTPC effectively reduces energetic disorder in active films. Moreover, extending the end conjugation not only broadens the absorption spectrum but also diminishes trap states and improves charge transport. Consequently, the YZ1-based organic photodetector exhibits an impressive detection range from 300 to 1050 nm with a high responsivity of 0.27 A W-1 at 1000 nm and specific detectivity of 9.24 x 10(13) Jones, comparable to commercial silicon photodiodes. Inspired by biological eyes, large-area parallelly independent photodetector arrays (2000 pixels) for an artificial vision system are fabricated, which enables a clear matter identification in the NIR region. These findings and results simultaneously provide critical insights into molecular design and bridge the gap between material science and device engineering, accelerating the application of NIR organic photodetectors in next-generation wearable optoelectronics.