A filterless organic photodetector electrically switchable between visible and infrared detection

Abstract

Wavelength tunable detectors are essential for capturing spectral information within diverse applications such as those related to object recognition and identification. Here, we present a generalizable design for a compact dual-band photodetector based on the integration of two back-to-back organic photodiodes that respond to visible (400–700 nm) and infrared light (700–1,400 nm). The polarity under external bias provides the electronic switch between visible and infrared detection modes. Operating at a low voltage of <1 V, the organic photodetector exhibits a fast response with a −3-dB cutoff frequency of 18 kHz and specific detectivity of 7.8 × 10 9 Jones. The device provides contactless measurements of high temperatures that originated from blackbody radiation and spectroscopic dual-band imaging for object identification. • Bias-switchable photodetection between visible and infrared sensing • Back-to-back diodes designed for tuning spectral ranges • Response speed of 18 kHz and low voltage of <1 V operation Li et al. report an organic dual-band photodetector with a switchable response to visible and IR spectral regions. The rapid response of tens of kHz is enabled by simple voltage control of <1 V. The device is based on back-to-back diodes, a configuration that may be generalizable to other thin-film optoelectronic materials.