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

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-TaIrTe4/n-type MoS2 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 x 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 TaIrTe4 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 x 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.

Automated summary

A T-d-TaIrTe4/n-type MoS2 van der Waals heterojunction photodetector with high responsivity and rectification ratio is reported in this study. The device takes advantage of the photovoltaic effect and the lateral built-in electric field. By utilizing the anisotropic crystalline structure of TaIrTe4, a high anisotropic ratio of the self-powered photocurrent is achieved. This work provides a valuable approach for highly integrated optoelectronic devices.