Flexible p-i-n InAs thin-film photodetector with low dark current enabled by an InAlAs barrier

Abstract

Flexible mid-infrared photodetectors are essential to realize advanced imaging applications, including wearable healthcare monitoring, security, and biomedical applications. Here, we demonstrate high-performance flexible p-i-n InAs thin-film photodetectors with an optimal In0.8Al0.2As barrier layer. This In0.8Al0.2As barrier inserted between p-InAs and UID-InAs layer reduced leakage currents by a factor of 283 by blocking the flow of electrons. The fabricated flexible device exhibited relatively low dark current densities of 1.03x10(-5) at 0 V and 0.85 A/cm(2) at -0.5 V, comparable to both commercially available and reported homoepitaxially-grown InAs detectors. Also, the high mechanical robustness and excellent reliability of our flexible InAs photodetector were confirmed by bending tests under various curvatures and bending cycles. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement