Insight into thermoelecric properties of Zigzag (8,0) boron nitride nanotube from first-principles calculations

Abstract

Boron nitride nanotubes are large-bandgap 1D naomaterials that combine unique physical characteristics making them attractive candidates towards thermoelectric (TE) applications. In the present paper, the TE properties of zigzag SWBNNT $(8,0)$ are investigated within first-principles density functional theory (DFT) combined with Boltzmann transport theory (BTT). The Seebeck coefficient (S), electrical ($\sigma / \tau$) and thermal ($\kappa / \tau$) conductivity, power factor (PF), and dimensionless figure of merit ($Z T$) are systematically explored as a function of the chemical potential ($\mu$) at different temperature. The results reveal negligible TE response close to the Fermi level owing to the intrinsic insulating character of the nanotube, whereas pronounced enhancements in the S and $P F$ occur near the valence/conduction band-edges. Furthermore, increasing temperatures significantly enhance charge carriers activation, leading to improved TE performance.