Naseri Mosayeb, Jalilian Jaafar, Salahub Dennis R, Lourenço Maicon Pierre, Rezaei Ghasem
Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah 67189-97551, Iran;
CMS-Center for Molecular Simulation, Department of Chemistry, Department of Physics and Astronomy, IQST-Institute for Quantum Science and Technology, Quantum Alberta, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
Computation (Basel). 2022 Jan 25;10(2):19. doi: 10.3390/computation10020019. eCollection 2022 Feb.
Employing first-principles calculations based on density functional theory (DFT), we designed a novel two-dimensional (2D) elemental monolayer allotrope of carbon called hexatetra-carbon. In the hexatetra-carbon structure, each carbon atom bonds with its four neighboring atoms in a 2D double layer crystal structure, which is formed by a network of carbon hexagonal prisms. Based on our calculations, it is found that hexatetra-carbon exhibits a good structural stability as confirmed by its rather high calculated cohesive energy -6.86 eV/atom, and the absence of imaginary phonon modes in its phonon dispersion spectra. Moreover, compared with its hexagonal counterpart, i.e., graphene, which is a gapless material, our designed hexatetra-carbon is a semiconductor with an indirect band gap of 2.20 eV. Furthermore, with a deeper look at the hexatetra-carbon, one finds that this novel monolayer may be obtained from bilayer graphene under external mechanical strain conditions. As a semiconductor with a moderate band gap in the visible light range, once synthesized, hexatetra-carbon would show promising applications in new opto-electronics technologies.
基于密度泛函理论（DFT）的第一性原理计算，我们设计了一种新型的二维（2D）碳元素单层同素异形体，称为六四碳。在六四碳结构中，每个碳原子在二维双层晶体结构中与其四个相邻原子键合，该结构由碳六棱柱网络形成。基于我们的计算，发现六四碳表现出良好的结构稳定性，其计算得到的相当高的内聚能-6.86 eV/原子以及声子色散谱中不存在虚声子模式证实了这一点。此外，与其六边形对应物即无带隙材料石墨烯相比，我们设计的六四碳是一种间接带隙为2.20 eV的半导体。此外，深入研究六四碳会发现，这种新型单层可能在外部机械应变条件下从双层石墨烯中获得。作为一种在可见光范围内具有适度带隙的半导体，一旦合成，六四碳将在新型光电子技术中显示出广阔的应用前景。
