Organic Sub-Bandgap Schottky Barrier Photodetectors with Near-Infrared Coherent Perfect Absorption

Abstract

Organic photodetectors (OPDs) show their advantages in flexibility, lightweight, and ultrathin form factors, large area compatibility, and low-cost manufacturability, but their absorption wavelengths are typically limited to the visible range. Although internal photoemission is a promising platform to achieve sub-bandgap photodetection in the near-infrared (NIR) or mid-IR wavelengths, very few studies have been reported for organic-based Schottky barrier photodetectors (SBPDs) operable in the NIR region. In this work, we experimentally demonstrate organic-based broadband NIR SBPDs. Our proposed SBPDs were designed by employing broadband single-channel coherent perfect absorption and therefore show high optical absorption as well as incident angle- and polarization-independent characteristics without any complex patterning processes. Our simple but effective SBPDs might open up new possibilities for OPDs in the extended operation wavelength ranges toward NIR in various sensing and imaging applications.