Ultrasensitive Room Temperature Infrared Photodetection Using a Narrow Bandgap Conjugated Polymer

Photodetectors operating across the short-, mid-, and long-wave infrared (SWIR-LWIR, lambda = 1-14 mu m) underpin modern science, technology, and society in profound ways. Narrow bandgap semiconductors that form the basis for these devices require complex manufacturing, high costs, cooling, and lack compatibility with silicon electronics, attributes that remain prohibitive for their widespread usage and the development of emerging technologies. Here, a photoconductive detector, fabricated using a solution-processed narrow bandgap conjugated polymer is demonstrated that enables charge carrier generation in the infrared and ultrasensitive SWIR-LWIR photodetection at room temperature. Devices demonstrate an ultralow electronic noise that enables outstanding performance from a simple, monolithic device enabling a high detectivity (D*, the figure of merit for detector sensitivity) >2.44 x 10(9) Jones (cm Hz(1/2) W-1) using the ultralow flux of a blackbody that mirrors the background emission of objects. These attributes, ease of fabrication, low dark current characteristics, and highly sensitive operation overcome major limitations inherent within modern narrow-bandgap semiconductors, demonstrate practical utility, and suggest that uncooled detectivities superior to many inorganic devices can be achieved at high operating temperatures.

Automated summary

Photodetectors operating in the infrared range play a crucial role in modern society, but their complex manufacturing, high costs, and lack of compatibility with silicon electronics have limited their widespread usage. This study introduces a solution-processed narrow bandgap conjugated polymer as a photoconductive detector, enabling ultrasensitive photodetection in the infrared range at room temperature. The device demonstrates outstanding performance, low electronic noise, and high detectivity, overcoming limitations of other narrow-bandgap semiconductors.