Electrical transport phenomena in two-dimensional metallic 2H-NbSe<sub>2</sub>: an experimental and theoretical study

Abstract

Two-dimensional (2D) metallic transition metal dichalcogenides (TMDCs) have attracted extensive interest in various fields owing to their unique electronic properties. However, studies on their transport properties and the modulation of these properties based on their band structure are limited. Herein, we studied the transport phenomena in 2D metallic 2H-NbSe2 using experimental and theoretical approaches. The transport properties, including electrical conductivity (sigma) and Seebeck coefficient (S), of mechanically exfoliated 2H-NbSe2 nanosheets were measured. We observed field effect-dependent variations in sigma and S of the 2H-NbSe2 nanosheets. Theoretical calculations of the electronic band structures and estimations of the transport properties of 2D 2H-NbSe2 crystals were conducted to verify and explain the experimental results. The superconducting transition temperature of the exfoliated NbSe2 nanosheets validated the reliability of the sample preparation procedures and indicated the high quality of the samples. Our findings provide a basis for understanding the electrical properties of metallic TMDCs intended for various applications.