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

Abstract

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.

Solution-processable infrared photodetectors: Materials, device physics, and applications

“…To improve the detector performance, efforts have been devoted to improving the charge mobility in the transport channel. For example, a planer structure is favorable [82] for molecular packing, which can be tuned to optimize the π-π stacking. In organic semiconductors, linear orientation and close packing of conjugated polymer backbones favor intermolecular transport and boost the photoresponse [82,83].…”

“…For example, a planer structure is favorable [82] for molecular packing, which can be tuned to optimize the π-π stacking. In organic semiconductors, linear orientation and close packing of conjugated polymer backbones favor intermolecular transport and boost the photoresponse [82,83]. In films of colloidal quantum dots, the conductance is improved by shortening or removing the surface ligands, because long ligands may block the charge transport between the nanocrystals [84,85].…”

Recent Advances in Solution‐Processable Organic Photodetectors and Applications in Flexible Electronics

“…A flexible SWIR OPD array was successfully fabricated on a PET substrate to detect spatial light intensity distribution. [161] X-ray imaging has been significantly applied in various applications, e.g., medical imaging, nondestructive testing in industrial products, and public security inspection. The detection of X-rays using OPDs is realized by indirect-conversion X-ray detectors combining scintillator and visible OPDs.…”

“…A flexible SWIR OPD array was successfully fabricated on a PET substrate to detect spatial light intensity distribution. [ 161 ]…”

Highly sensitive, sub-microsecond polymer photodetectors for blood oxygen saturation testing

“…The D* is one of significant parameters for photodetectors to evaluate detection ability [43][44][45][46]. Achieving J d as low as possible is conducive to realizing high D* [47][48][49][50][51][52]. The D* can be calculated from dark current (I d ) if the noise is mostly dominated by shot noise (i s ).…”