Prediction of a new two-dimensional metallic carbon allotrope
Prediction of a new two-dimensional metallic carbon allotrope
复制标题
新型二维金属碳同素异形体的预测
DOI：
10.1039/c2cp43070c
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Wang, Jian-Tao
中科院分区：
文献类型：
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作者：
Wang, Xin-Quan;Li, Han-Dong;Wang, Jian-Tao
通过第一性原理计算，我们预测了具有Cmmm （D-2h(19)）对称性的新型金属二维碳同素异形体net W。这种新的碳相由正方形C-4、六边形C-6和八边形C-8组成，基于声子模式分析验证了它的动力学稳定性，并且在能量上比先前提出的二维碳形式（如净碳、平面C-4、联苯、石墨炔和最近制备的石墨炔）更有利。另一方面，由于碳p(z)轨道在费米能级上的态密度相当大，我们发现净W具有很强的金属丰度。通过第一性原理分子动力学模拟，我们从理论上证明了平行排列的最窄角多环芳烃（4-AGNRs）的选择性脱氢会导致自发相互转化为这种净W碳相，并指出了可能的合成途径。特别有趣的是，当净W碳片被切割成一定宽度的带状时，可以引入半导体性。我们的工作表明，净W碳片及其纳米带在未来的纳米电子学中具有巨大的潜力。
By means of the first-principles calculations, we predict a new metallic two-dimensional carbon allotrope named net W with Cmmm (D-2h(19)) symmetry. This new carbon phase consists of squares C-4, hexagons C-6, and octagons C-8, its dynamical stability is validated based on phonon-mode analysis and it is energetically more favored over previously proposed two-dimensional carbon forms such as net C, planar C-4, biphenylene, graphyne, and the recently prepared graphdiyne. On the other hand, we find that net W possesses strong metallicity due to its rather large density of states across the Fermi level contributed by the carbon p(z) orbital. Through first-principles molecular dynamics simulations, we theoretically demonstrate that selective dehydrogenation of the parallel-laid narrowest angular polycyclic aromatic hydrocarbons (4-AGNRs) would lead to a spontaneous interconversion to such a net W carbon phase, the possible synthetic routes are also addressed. Of particular interest, semiconductivity could be introduced when a net W carbon sheet is cut into ribbons of certain widths. Our work shows that the net W carbon sheet and its nanoribbons have great potential for future nanoelectronics.