Department of Physics, Amirkabir University of Technology, PO Box 15875-4413, Tehran, Iran.
Nanotechnology. 2016 Jul 8;27(27):275704. doi: 10.1088/0957-4484/27/27/275704. Epub 2016 May 31.
Density-functional theory (DFT) was applied to investigate the geometry and electronic properties of bare Si60 and H-terminated Si-fullerene. DFT predicts outward sites on a bare Si60 cage. By using π-orbital axis analysis (POAV), it is shown that these sites result from a strong tendency of silicon atoms to form sp(3) hybridization bonds. Natural bond orbital (NBO) analysis confirms the sp(3) hybridization nature of Si-Si bonds in Si-fulleranes. The quantum confinement effect (QCE) does not affect band gap (BG) so strongly in the size between 1 and 1.7 nm. In contrast, the geometry and symmetry of the cage have a significant influence on the BG. In contrast to their carbon analogs, pentagon rings increase the stability of the cages. Functionalized Si-cages are stable and can be chemically very active. The electronic properties are highly sensitive to the surface chemistry via functionalization with different chemical groups. As a result, BGs and chemical activities of these cages can be drastically tuned through the chemistry of the surface.
密度泛函理论（DFT）被应用于研究裸 Si60 和 H 封端 Si 富勒烯的几何和电子性质。DFT 预测裸 Si60 笼的外点位。通过使用π轨道轴分析（POAV），表明这些位是由于硅原子形成 sp(3)杂化键的强烈趋势所致。自然键轨道（NBO）分析证实了 Si 富勒烯中 Si-Si 键的 sp(3)杂化性质。在 1 到 1.7nm 的尺寸范围内，量子限制效应（QCE）对带隙（BG）的影响并不强烈。相比之下，笼的几何形状和对称性对 BG 有显著影响。与它们的碳类似物相比，五元环增加了笼的稳定性。官能化的 Si 笼是稳定的，并且可以具有非常高的化学活性。通过与不同的化学基团进行官能化，电子性质对表面化学高度敏感。因此，通过表面化学修饰，可以大大调节这些笼的 BG 和化学活性。
