Exploration of structural, electrical, and thermoelectric properties of two-dimensional WTe2 in three phases through ab initio investigations

Abstract

In this study, the structural, electrical, and thermoelectric properties for three phases of two-dimensional ${\mathrm{WTe}}_2$ have been investigated using first-principles study and semiclassic Boltzmann theory. The results of the electronic density of states have represented band gaps of 1.026, 1.021, and 1.048 eV for phase 1, phase 2, and phase 3, respectively. Furthermore, the largest value of the Seebeck coefficient at 300 K belonged to phase 2 with a value of 1585.21 $\mu$V/K at the chemical potential of 0.45 eV. In addition, the largest value of electrical conductivity per relaxation time was related to phase 1 at 300 K with the value of 3.42 × 10²⁰ ${\Omega }^{-1}$ m⁻¹ s⁻¹ at the chemical potential of -1.94 eV. Moreover, the largest value of the thermoelectric power factor per relaxation time occurred for phase 1 at 700 K with a value of 48.62 × 10¹⁶ $\mu$W m⁻¹ K⁻² s⁻¹ at the chemical potential of -1.17 eV.