Highly In-Plane Anisotropic Two-Dimensional Ternary Ta₂NiSe₅ for Polarization-Sensitive Photodetectors

Intriguing anisotropic electrical and optoelectrical properties in two-dimensional (2D) materials are currently gaining increasing interest both for fundamental research and emerging optoelectronic devices. Identifying promising new 2D materials with low-symmetry structures will be rewarding in the development of polarization-integrated nanodevices. In this work, the anisotropic electron transport and optoelectrical properties of multilayer 2D ternary Ta₂NiSe₅ were systematically researched. The polarization-sensitive Ta₂NiSe₅ photodetector shows a linearly anisotropy ratio of ≈3.24 with 1064 nm illumination. The multilayer Ta₂NiSe₅-based field-effective transistors exhibit an excellent field-effective mobility of 161.25 cm²·V^-1·s^-1 along the a axis (armchair direction) as well as a great current saturation characteristic at room temperature. These results will promote a better understanding of the optoelectrical properties and applications in new categories of the in-plane anisotropic 2D materials.