Hysteresis-controlled Van der Waals tunneling infrared detector enabled by selective layer heating

Abstract

Mid-infrared (mid-IR) photodetectors play a crucial role in various applications, including the development of biomimetic vision systems that emulate neuronal function. However, current mid-IR photodetector technologies are limited by their cost and efficiency. In this work, we demonstrate a new type of photodetector based on a tunnel structure made of two-dimensional materials. The effect manifests when the upper and lower layers of the tunnel structure are heated differently. The photoswitching is threshold-based and represents a ``jump'' in voltage to another branch of the current-voltage characteristic when illuminated at a given current. This mechanism provides enormous photovoltage (0.05$-$1~V) even under weak illumination. Our photodetector has built-in nonlinearity and is therefore an ideal candidate for use in infrared vision neurons. Additionally, using this structure, we demonstrated the possibility of selective heating of layers in a van der Waals stack using mid-IR illumination. This method will allow the study of heat transfer processes between layers of van der Waals structures, opening new avenues in the physics of phonon interactions.