Anti-ambipolar and polarization-resolved behavior in MoTe₂channel sensitized with low-symmetric CrOCl

Atomically thin two-dimensional (2D) materials make it possible to create a variety of van der Waals (vdW) heterostructures with different physical features and attributes, which enables the growth of innovative electronics and optoelectronics applications. The band alignment and charge transfer play a crucial role in the physical and optoelectrical properties of the vdW heterostructure. Here, we design a vdW heterojunction device comprising low-symmetric CrOCl to induce a stable anti-ambipolar behavior and polarization-sensitive photodetection performance. 2D CrOCl exhibits strong in-plane anisotropy and linear dichroism, and an anti-ambipolar transport behavior is observed in a MoTe2 channel due to the gate-tunable band bending and charge transfer at MoTe2/CrOCl interface. The devices also exhibit well photodetection performance with a responsivity of 1.05 A/W and a temporal response of 970 μs. Owing to the anisotropic CrOCl serving as a photosensitizing layer, the device achieves the capability of polarization-sensitive photodetection with a photocurrent dichroic ratio up to ∼6. This work offers a valid device model and design strategy to realize the versatile optoelectronics, including the anti-ambipolar transistor and polarimetric photodetectors.