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

Abstract

High-performance\nshort-wave infrared (SWIR) photodetectors (PDs)\npossess great potential in health monitoring, remote control, telecommunication,\nand medical diagnostics. In comparison with inorganic PDs, organic\nPDs (OPDs) stand out as good candidates for next-generation photodetection\ndevices because of their ease of processing, tunable optoelectronic\nproperties, lightweight, easy portability, and low-manufacturing cost.\nHerein, we reported two conjugated polymers with ultranarrow band\ngaps (0.6 eV) for photoconductor-mode SWIR OPDs, which exhibited broad\nand excellent photoresponse across the visible and IR regions as long\nas 1450 nm. Specifically, one of the polymers possessing longer exciton\nlifetimes and favorable morphology and molecular orientation was further\napplied for flexible OPDs, demonstrating excellent performance with\nthe responsivity (<i>R</i>) and external quantum efficiency\nas high as 0.96 A/W and 106% at 1122 nm, respectively, comparable\nto those of 2D nanomaterial-based IR PDs. In addition, an image sensor\ncomposed of 16 × 16 flexible OPDs was constructed, which can\ndetect spatial light intensity distribution (1342 nm) clearly. This\ncontribution shed light on designing excellent conjugated polymers\nfor high-performance photoconductor-mode OPDs, which can be employed\nfor SWIR light image sensors.