Band-Gap Engineering via Tailored Line Defects in Boron-Nitride Nanoribbons, Sheets, and Nanotubes
Band-Gap Engineering via Tailored Line Defects in Boron-Nitride Nanoribbons, Sheets, and Nanotubes
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通过氮化硼纳米带、片材和纳米管中的定制线缺陷进行带隙工程
DOI：
10.1021/nn300495t
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发表时间：
2012-05-01
期刊：
影响因子：
17.1
通讯作者：
Yang, Jinlong
中科院分区：
文献类型：
--
作者：
Li, Xiuling;Wu, Xiaojun;Yang, Jinlong
我们使用第一性原理计算和Born-Oppenheimer量子分子动力学模拟，对单层氮化硼（BN）片、纳米带和单壁BN纳米管的线缺陷对电子和磁性的影响进行了全面研究。虽然线缺陷划分的BN片（或纳米管）域，我们表明，某些线缺陷可以导致定制的边缘BN片（或不完美的纳米管），可以显着降低BN片或纳米管的带隙。特别是，我们发现，线缺陷嵌入锯齿形BN纳米带（LD-zBNNRs）的化学均匀的边缘，如B-或N-终止的边缘可以实现通过引入一个B-2，N-2，或C-2五边形-八角形-五边形（5-8-5）线缺陷或通过创建的反位线缺陷。只有B-终止的边缘的LD-zBNNRs被预测为在基态的反铁磁半导体，而只有N-终止的边缘的LD-zBNNRs是金属与简并的反铁磁和铁磁状态。此外，我们发现，氢钝化的LD-zBNNRs以及线缺陷嵌入BN片（和纳米管）是具有显着降低的带隙的半导体。带隙的减少归因于线缺陷引起的杂质态。线缺陷嵌入BN纳米材料的潜在应用包括纳米电子和自旋电子器件。
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-defect-embedded BN nanomaterials include nanoelectronic and spintronic devices.