Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, Puebla, México.
J Mol Model. 2012 May;18(5):2147-52. doi: 10.1007/s00894-011-1235-9. Epub 2011 Sep 25.
Using first-principles total energy calculations within the density functional theory (DFT), we investigated the electronic and structural properties of graphene-like silicon sheets. Our studies were performed using the LSDA (PWC) and GGS (PBE) approaches. Two configurations were explored: one corresponding to a defect-free layer (h-Si), and the other to a layer with defects (d-Si), both of which were in the armchair geometry. These sheets contained clusters of the C(n)H(m) type. We also investigated the effects of doping with group IV-A elements. Structural stability was studied by only considering positive vibration frequencies. Results showed that both h-Si and d-Si present a corrugated structure with concavity. h-Si sheets were found to be ionic (D.M. = 0.33 Debye) with an energy gap (HOMO-LUMO) of 0.77 eV in the LSDA theory and 0.76 eV in the GGS approach, while d-Si sheets were observed to be covalent (D.M. = 2.78 D), and exhibited semimetallic electronic behavior (HOMO-LUMO gap = 0.32 eV within the LSDA theory and 0.33 eV within the GGS approach). d-Si sheets doped with one carbon or one germanium preserved the polarity of the undoped d-Si sheets, as well as their semimetallic electronic behavior. However, when the sheets were doped with two C or two Ge atoms, or with one of each atom (to give Si(52)CGeH(18)), they retained the semimetallic behavior, but they changed from having ionic character to covalent character.
使用第一性原理的密度泛函理论（DFT）总能量计算，我们研究了类石墨烯硅片的电子和结构性质。我们的研究使用了 LSDA（PWC）和 GGS（PBE）方法。我们探索了两种构型：一种对应于无缺陷层（h-Si），另一种对应于具有缺陷的层（d-Si），两者均为扶手椅几何形状。这些片层包含 C(n)H(m) 类型的团簇。我们还研究了掺杂 IVA 族元素的影响。通过仅考虑正振动频率来研究结构稳定性。结果表明，h-Si 和 d-Si 都呈现出凹陷的波纹结构。h-Si 片层被发现是离子的（D.M. = 0.33 德拜），在 LSDA 理论中能隙（HOMO-LUMO）为 0.77 eV，在 GGS 方法中为 0.76 eV，而 d-Si 片层被观察到是共价的（D.M. = 2.78 D），并表现出半导体电子行为（HOMO-LUMO 能隙在 LSDA 理论中为 0.32 eV，在 GGS 方法中为 0.33 eV）。用一个碳或一个锗掺杂的 d-Si 片层保留了未掺杂 d-Si 片层的极性和半导体电子行为。然而，当片层用两个 C 或两个 Ge 原子掺杂，或用每个原子的一个掺杂（得到 Si(52)CGeH(18)）时，它们保留了半导体行为，但它们从离子特性转变为共价特性。
