Electronic and piezoelectric properties of BN nanotubes from hybrid density functional method

TL;DR

This study uses hybrid density functional calculations to explore the electronic and piezoelectric properties of BN nanotubes, revealing larger band gaps and promising piezoelectric constants for nanoelectromechanical applications.

Contribution

It provides a detailed first-principles analysis of BN nanotubes' electronic and piezoelectric properties using the B3LYP hybrid functional, offering insights consistent with GW results.

Findings

B3LYP band gap exceeds LDA by about 1.8 eV for nanotubes.

Optical absorption line at 4.45 eV may be due to electron transition in small zigzag BN nanotubes.

Piezoelectric constants are significantly larger than in PVDF, indicating potential for nanoelectromechanical devices.

Abstract

The electronic and piezoelectric properties of the boron nitride (BN) nanotubes are investigated with the hybrid density functional (B3LYP) method. We first study bulk h-BN and BN sheet and find that the B3LYP band structure and energy gap are consistent with the GW results. The B3LYP band gap is larger than the LDA one by about 1.8 eV for both zigzag and armchair nanotubes with various radius. We give an alternative interpretation that the optical absorption lines at 4.45 eV might be due to the electron transition in small zigzag BN nanotubes. The piezoelectric constant from the B3LYP method for zigzag BN nanotubes are substantially larger than those in the PVDF polymer family, suggesting BN nanotubes as candidates for various nanoelectromechanical applications.