Induced polarization and electronic properties of carbon doped boron-nitride nanoribbons

TL;DR

This study uses density functional calculations to explore how carbon doping affects the electronic and polarization properties of boron-nitride nanoribbons, revealing tunable energy gaps and polarization behaviors.

Contribution

It provides new insights into how different carbon doping configurations influence the electronic properties and polarization of boron-nitride nanoribbons, including electric field effects.

Findings

NCB arrangement is strongly polarized with a large dipole moment.

Doping reduces the band gap regardless of local arrangement.

Electric field can tune the energy gap and polarization.

Abstract

The electronic properties of boron-nitride nanoribbons (BNNRs) doped with a line of carbon atoms are investigated by using density functional calculations. Three different configurations are possible: the carbon atoms may replace a line of boron or nitrogen atoms or a line of alternating B and N atoms which results in very different electronic properties. We found that: i) the NCB arrangement is strongly polarized with a large dipole moment having an unexpected direction, ii) the BCB and NCN arrangement are non-polar with zero dipole moment, iii) the doping by a carbon line reduces the band gap independent of the local arrangement of boron and nitrogen around the carbon line, iv) an electric field parallel to the carbon line polarizes the BN sheet and is found to be sensitive to the presence of carbon dopants, and v) the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases linearly with increasing applied electric field directed parallel to the carbon line. We show that the polarization and energy gap of carbon doped BNNRs can be tuned by an electric field applied parallel along the carbon line.