Gate‐Tunable Photovoltaic Behavior and Polarized Image Sensor Based on All‐2D TaIrTe4/MoS2 Van Der Waals Schottky Diode

Abstract 2D Weyl semimetal shows potential applications in photodetection, polarization‐sensitive imaging, and Schottky barrier diodes, due to its unique band structure and topological nature. However, its inherently large dark current hinders further improvements of the Weyl semimetal‐based photodetector's performance. Herein, a T d ‐TaIrTe 4 /n‐type MoS 2 van der Waals (vdWs) heterojunction photodetector is reported. Owing to the effective lateral build‐in electric field of 145.3 meV, the Schottky diode shows a high rectification ratio of 6 × 10 3 . Benefiting from the photovoltaic effect, a maximum responsivity ( R ) of 750 mA W −1 and an I on / I off ratio of 10 4 under 635 nm illumination are achieved. What's more, the photovoltaic R can be enhanced to 890 mA W −1 at the V g of 40 V. Because of the highly anisotropic crystalline structure of TaIrTe 4 component, a high self‐powered photocurrent anisotropic ratio up to 4.19 is realized under 635 nm light at V g = 40 V. Under self‐powered mode, a high‐resolution letter of “T” within 150 × 120 pixels can be displayed when the polarization direction is parallel to the armchair direction, while it becomes weak along the zigzag direction. This work provides a valuable route to fabricate anisotropic Weyl semimetal/semiconductor vdWs junction for highly integrated optoelectronics.