Institut des Matériaux Jean Rouxel, UMR CNRS, University of Nantes, France.
Phys Rev Lett. 2011 Aug 5;107(6):065502. doi: 10.1103/PhysRevLett.107.065502.
We demonstrate that free graphene sheet edges can curl back on themselves, reconstructing as nanotubes. This results in lower formation energies than any other nonfunctionalized edge structure reported to date in the literature. We determine the critical tube size and formation barrier and compare with density functional simulations of other edge terminations including a new reconstructed Klein edge. Simulated high resolution electron microscopy images show why such rolled edges may be difficult to detect. Rolled zigzag edges serve as metallic conduction channels, separated from the neighboring bulk graphene by a chain of insulating sp(3)-carbon atoms, and introduce van Hove singularities into the graphene density of states.
我们证明了游离的石墨烯边缘可以自行卷曲，形成纳米管。与文献中迄今为止报道的任何其他非官能化边缘结构相比，这种结构的形成能更低。我们确定了临界管尺寸和形成势垒，并与其他边缘终止的密度泛函模拟进行了比较，包括新的重构 Klein 边缘。模拟的高分辨率电子显微镜图像显示了为什么这样的卷曲边缘可能难以检测。卷曲的锯齿形边缘充当金属传导通道，与相邻的体石墨烯通过一系列绝缘的 sp(3)-碳原子链隔开，并在石墨烯的态密度中引入了 van Hove 奇点。
