Ultrahigh-Performance Self-Powered Flexible Photodetector Driven from Photogating, Piezo-Phototronic, and Ferroelectric Effects

Owing to the need for dynamic, real-time, and on-site data collection in internet of things applications, the realization of ultra-sensitive sensing networks with self-powered, flexible, and lightweight devices has become an important issue for the development of sensor systems. In this work, a novel, high-performance, self-powered photodetector is achieved through the combination of photogating, piezo-phototronic, and ferroelectric effect by incorporating a ferroelectric thin film of poly(vinylidene fluoride-co-trifluoroethylene) in a rationally designed device structure with suitable band alignment, which can modulate carrier transport behavior at the interface due to the internal electric field produced by light illumination, external strain, or voltage-poled dipole. This enables photocurrent and overall device performance to improve significantly. The unprecedented photodetector presented in this study has several merits, including mechanical flexibility and light weight that allow it to adapt to arbitrary surface topology; additionally, its self-powering capability and high reliability are urgently needed for the demanding functionality of devices for the development of next-generation optoelectronic devices, spanning from wearable communication to unattended harsh environments with a human-friendly interface.