Flexible Short-Wave Infrared Image Sensors Enabled by High-Performance Polymeric Photodetectors

High-performance short-wave infrared (SWIR) photodetectors (PDs) possess great potential in health monitoring, remote control, telecommunication, and medical diagnostics. In comparison with inorganic PDs, organic PDs (OPDs) stand out as good candidates for next-generation photodetection devices because of their ease of processing, tunable optoelectronic properties, lightweight, easy portability, and low-manufacturing cost. Herein, we reported two conjugated polymers with ultranarrow band gaps (0.6 eV) for photoconductor-mode SWIR OPDs, which exhibited broad and excellent photoresponse across the visible and IR regions as long as 1450 nm. Specifically, one of the polymers possessing longer exciton lifetimes and favorable morphology and molecular orientation was further applied for flexible OPDs, demonstrating excellent performance with the responsivity (R) and external quantum efficiency as high as 0.96 A/W and 106% at 1122 nm, respectively, comparable to those of 2D nanomaterial-based IR PDs. In addition, an image sensor composed of 16 × 16 flexible OPDs was constructed, which can detect spatial light intensity distribution (1342 nm) clearly. This contribution shed light on designing excellent conjugated polymers for high-performance photoconductor-mode OPDs, which can be employed for SWIR light image sensors.