Modulation of electronic and thermal properties of boron phosphide nanotubes under electric and magnetic fields

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2025-01, Vol.165, p.116125, Article 116125
• Main Authors: Rashidi, Nooshin, Moradian, Rostam
• Format: Article
• Language: English
• Subjects: Boron phosphide nanotubes; Electric and magnetic fields; Thermoelectric properties
• ISSN: 1386-9477
• DOI: 10.1016/j.physe.2024.116125

This work theoretically investigates the thermoelectric properties of boron phosphide nanotubes (BPNTs) using the tight-binding model, Green function method, and Kubo formalism, focusing on a zigzag BPNT with indices (20, 0). The tight binding parameters obtained by matching its band structure with calculated density functional theory band structure. The study examines the effects of transverse electric fields and axial magnetic fields on various physical properties, such as band structure, density of states (DOS), heat capacity, magnetic susceptibility, and other thermoelectric properties. BPNTs consistently show semiconducting properties with a nearly 1 eV direct band gap. The electronic properties of BPNTs are significantly affected by applied electric field, which at very strong strengths can induce a semiconducting to metallic phase transition. In contrast, the magnetic field leads to the splitting of energy bands, especially around the Fermi level. The DOS also changes with the electric field, including variations in the position, intensity, and number of DOS peaks. The thermal properties and thermoelectric performance of BPNTs are temperature-dependent. Increasing of excited electrons thermal energy cause more occupation of high energy levels in the conduction bands. The electric field further enhances the thermal properties of BPNTs by modifying their electronic properties and reducing the band gap. Stronger electric fields cause a noticeable enhancement in the BPNTs thermal properties because it is increasing the concentration of excited charge carriers. This aspect is crucial for improving the thermoelectric efficiency of BPNTs, making them more competitive for practical applications. ●We investigate the effect of a transverse electric field and an axial magnetic field on the thermoelectric properties of a (20, 0) boron phosphide nanotube (BPNT).●By fitting the tight-binding model band structure of a 2D h-BP with its calculate DFT band structure, the first three hopping integrals obtained as 1.9 eV, 2.2 eV, and 0.205 eV. The onsite energies are determined as 1.62 eV for boron atoms and 2.61 eV for phosphide atoms.●Applying a transverse electric field reduces the energy gap. At very strong fields it could leading to a semiconducting-to-metallic phase transition. As the electric field strength increases from zero to 0.02, 0.04, and 0.08 eV/Å, the band gap gradually decreases to the 0.8, 0.52 and 0.3 eV, respectively. [Display omitted]