Self‐Powered Broadband Photodetector with Fast Photoresponse and Low Dark Current Based on Gr/MoTe ₂ /NbSe ₂ Heterostructure

ABSTRACT The strong Fermi pinning effect at interfaces between bulk metallic electrodes and 2D semiconductors presents a significant challenge for developing high‐performance 2D Schottky photodetectors with simultaneous fast response and high detectivity. Herein, we demonstrate a high‐performance self‐powered photodetector based on an all‐2D van der Waals (vdW) heterojunction, utilizing metallic 2H‐NbSe 2 and graphene as vdW electrodes interfaced with semiconducting MoTe 2 . Leveraging Schottky barriers and a built‐in electric field, the device achieves zero‐bias operation with a rapid response speed (749 ns/313 ns), low dark current (∼2 × 10 −13 A), a high detectivity of 1.14 × 10 12 Jones, and broadband photodetection from visible to near‐infrared (450–1064 nm). Moreover, the device has been successfully implemented in imaging systems and infrared optical communications, demonstrating its potential for practical applications. This work highlights the promising potential of the 2D vdW metallic electrodes to construct a high‐performance Schottky heterojunction photodetector.