Observation of large in-plane anisotropic transport in van der Waals semiconductor Nb2SiTe4

Two-dimensional (2D) van der Waals material is a focus of research for its widespread application in optoelectronics, memories, and spintronics. The ternary compound Nb₂SiTe₄ is a van der Waals semiconductor with excellent air stability and small cleavage energy, which is suitable for preparing a few layers counterpart to explore novel properties. Here, properties of bulk Nb₂SiTe₄ with large in-plane electrical anisotropy are demonstrated. It is found that hole carriers dominate at a temperature above 45 K with a carrier active energy of 31.3 meV. The carrier mobility measured at 100 K is about 213 cm²·V^-1·s^-1 in bulk Nb₂SiTe₄, higher than the reported results. In a thin flake Nb₂SiTe₄, the resistivity ratio between the crystalline axes of a and b is reaching about 47.3 at 2.5 K, indicating that there exists a large anisotropic transport behavior in their basal plane. These novel transport properties provide accurate information for modulating or utilizing Nb₂SiTe₄ for electronic device applications.