论文标题
新的稳定二维硅碳化物纳米片
New stable two dimensional silicon carbide nanosheets
论文作者
论文摘要
我们预测采用从头算密度功能理论计算的新的二维二维碳化硅纳米结构的存在。这些结构由四角环和六角形环组成，该环与屈曲平面上的C-C和Si-C键组成。事实证明，它们在热力学和机械上具有相对较低的地层能量，这意味着在实验室中的潜在制造。它们表现出强烈的延展性和各向异性，其应变压力关系和机械模量的定向依赖性。材料在使用奇妙的延性特性的机械应变时保持了声子稳定性。 SIC2结构具有使用HSE06功能预测的0.02 EV的微小直接带隙，并且可以通过多种方法（例如氢化和应变施用）开放带隙。差距值可以在0.02〜1.72 eV的范围内进行策略性调整，并且可以进一步操纵直接/间接间隙性质。相比之下，SIC的紧密相关结构显示了1.80 eV的间接HSE带隙和应变工程的值在0.0〜1.95 eV之间。这些新提出的结构中的独特性能可能在未来的纳米力学和电子产品中具有潜在的应用。
We predict the existence of new two dimensional silicon carbide nanostructure employing ab initio density-functional theory calculations. These structures are composed of tetragonal and hexagonal rings with C-C and Si-C bonds arranged in a buckling plane. They are proven to be thermodynamically and mechanically stable with relatively low formation energy, implying potential fabrication in lab. They exhibit strong ductility and anisotropicity from their strain-stress relation and directional dependence of mechanical moduli. The materials maintain phonon stability upon the application of mechanical strain up to 27% with fantastic ductile property. The SiC2 structure possesses a tiny direct band gap of 0.02 eV predicted using HSE06 functional and the band gap can be opened up through multiple approaches such as hydrogenation and strain application. The gap values can be strategically tuned in the range of 0.02 ~ 1.72 eV and the direct/indirect gap nature can be further manipulated. In contrast, a closely related structure of SiC shows an indirect HSE band gap of 1.80 eV and strain engineering its value between 0.0 ~ 1.95 eV. The unique properties in these newly proposed structures might have potential applications in future nanomechanics and electronics.
