Complex temperature-dependent electrical and magneto-transport properties in layered semiconductor Nb2SiTe4 crystals

Abstract

The compound Nb₂SiTe₄ is a newly discovered layered narrow-band-gap semiconductor material that shows large infrared-electromagnetic-wave response and high carrier mobility. Here, we grew Nb₂SiTe₄ crystals using the chemical-vapor-transport method and systematically investigated its electrical and magneto-transport properties. Nb₂SiTe₄ exhibits the semiconductor behavior. More detailed analyses indicate that: at high temperatures (T > 30 K), the logarithmic resistivity of Nb₂SiTe₄ shows a T⁻¹ dependence, inferring the thermal activation behavior; at middle temperature range (12K < T < 30 K), it changes to a T^−1/3 dependence, being consistent with two-dimensional variable-range-hopping mechanism; finally, at low temperature range (T < 7 K), the electron-electron interaction is the major factor to the resistance of Nb₂SiTe₄. Simultaneously, magneto-resistance demonstrates a temperature-induced transition from weak antilocalization to weak localization at about 7 K, which is in line with evolution of the temperature-dependent resistivity. Analysis of temperature-dependent phase coherence length L_φ by the Nyquist dephasing model infers that electron-electron interaction results in the de-phasing of electron wave at low temperature. We qualitatively explain the evolution of electrical and magneto-transport properties based on the thermally-excited carrier concentrations at different temperatures and corresponding screened Coulomb interaction. This work enriches the understanding of transport properties of layered semiconductor compounds similar to Nb₂SiTe₄.