Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun, 130022, China.
Sci Rep. 2013;3:1524. doi: 10.1038/srep01524.
Based on a newly developed size-dependent cohesive energy formula for two-dimensional materials, a unified theoretical model was established to illustrate the gap openings in disordered graphene flakes, involving quantum dots, nanoribbons and nanoporous sheets. It tells us that the openings are essentially dominated by the variation in cohesive energy of C atoms, associated to the edge physicochemical nature regarding the coordination imperfection or the chemical bonding. In contrast to those ideal flakes, consequently, the gaps can be opened monotonously for disordered flakes on changing their sizes, affected by the dimension, geometric shape and the edge saturation. Using the density functional theory, accordingly, the electronic structures of disordered flakes differ to the ideal case because of the edge disorder. Our theoretical predictions have been validated by available experimental results, and provide us a distinct way for the quantitative modulation of bandgap in graphene for nanoelectronics.
基于新开发的二维材料尺寸相关内聚能公式，建立了一个统一的理论模型来解释无序石墨烯片（包括量子点、纳米带和多孔片）中的间隙开口。它告诉我们，开口本质上主要由 C 原子内聚能的变化决定，与边缘的物理化学性质（关于配位不完善或化学键）有关。因此，与理想薄片相比，无序薄片的尺寸变化会使其间隙单调地打开，这受到尺寸、几何形状和边缘饱和的影响。相应地，使用密度泛函理论，由于边缘无序，无序薄片的电子结构与理想情况不同。我们的理论预测已经被现有的实验结果所验证，并为我们提供了一种在纳米电子学中定量调节石墨烯能带隙的独特方法。
