Abstract
We perform a comprehensive study of the effects of line defects on electronic and magnetic properties of monolayer boron-nitride (BN) sheets, nanoribbons, and single-walled BN nanotubes using first-principles calculations and Born-Oppenheimer quantum molecular dynamic simulation. Although line defects divide the BN sheet (or nanotube) into domains, we show that certain line defects can lead to tailor-made edges on BN sheets (or imperfect nanotube) that can significantly reduce the band gap of the BN sheet or nanotube. In particular, we find that the line-defect-embedded zigzag BN nanoribbons (LD-zBNNRs) with chemically homogeneous edges such as B- or N-terminated edges can be realized by introducing a B 2, N 2, or C 2 pentagon-octagon-pentagon (5-8-5) line defect or through the creation of the antisite line defect. The LD-zBNNRs with only B-terminated edges are predicted to be antiferromagnetic semiconductors at the ground state, whereas the LD-zBNNRs with only N-terminated edges are metallic with degenerated antiferromagnetic and ferromagnetic states. In addition, we find that the hydrogen-passivated LD-zBNNRs as well as line-defect-embedded BN sheets (and nanotubes) are nonmagnetic semiconductors with markedly reduced band gap. The band gap reduction is attributed to the line-defect-induced impurity states. Potential applications of line-defectembedded BN nanomaterials include nanoelectronic and spintronic devices.
Original language | English (US) |
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Pages (from-to) | 4104-4112 |
Number of pages | 9 |
Journal | ACS Nano |
Volume | 6 |
Issue number | 5 |
DOIs | |
State | Published - May 22 2012 |
Keywords
- Band gap reduction
- H-BN sheet
- Line defect
- Nanoribbon
- Nanotube
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)