Fourfold Polarization-Sensitive Photodetector Based on GaTe/MoS2 van der Waals Heterojunction

Integrated polarization-sensitive photodetectors fabricated by geometric anisotropic 2D materials have become attractive in recent years. In this work, the successful construction of self-driven and polarization-sensitive photodetectors based on GaTe/MoS2 p-n van der Waals (vdW) heterojunction is demonstrated by mechanical exfoliation and dry transfer methods. The fabricated GaTe/MoS2 vdW heterojunctions show ambipolar behavior, and the highest rectification ratio can reach 93.4. The highest responsivity under 532 nm illumination reaches 145 mA W-1 and the response time is less than 10 ms. Moreover, the photocurrent polarization of the fabricated GaTe/MoS2 photodetectors manifests in fourfold anisotropy with a high polarization ratio of 2.9, which can be ascribed to the highly anisotropic monoclinic structure of layered m-GaTe. This finding thus offers more information and creates new opportunities about how to fabricate integrated polarization-sensitive photodetectors.