Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Nanoscale. 2017 May 11;9(18):5854-5858. doi: 10.1039/c7nr00762k.
Recently, there has been a growing interest in exploring planar hypercoordinate carbons in two-dimensional nanostructures. However, atomic monolayers with ideal planar hypercoordinate carbon are quite rare due to the challenge in stabilizing the exotic motifs. We predicted a global minimum two-dimensional BeC monolayer using the global particle-swarm optimization method. Each carbon binds peripheral four atoms in the same plane, forming a perfectly planar tetracoordinate carbon moiety. The cohesive energy, phonon-spectrum and mechanical stability criteria confirm the stability of monolayer BeC. In addition, the BeC monolayer has a large in-plane stiffness (145.54 N m) and thermo-dynamical stability (up to 2000 K). Furthermore, BeC is an indirect semiconductor with a band gap of 1.01 eV and possesses exceptionally high carrier mobilities (∼10 cm V s), rendering it suitable for application in electronics and photoelectronics.
最近，人们对探索二维纳米结构中的平面高坐标碳越来越感兴趣。然而，由于稳定奇异结构的挑战，具有理想平面高坐标碳的原子单层相当罕见。我们使用全局粒子群优化方法预测了二维 BeC 单层的全局最小值。每个碳原子与同一平面上的四个外围原子结合，形成一个完全平面的四配位碳部分。结合能、声子谱和力学稳定性标准证实了单层 BeC 的稳定性。此外，BeC 单层具有较大的面内刚度（145.54 N m）和热动力学稳定性（高达 2000 K）。此外，BeC 是一种间接半导体，带隙为 1.01 eV，载流子迁移率极高（约 10 cm V s），适用于电子学和光电子学应用。
