Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89081 Ulm, Germany.
Beilstein J Nanotechnol. 2014 Jan 6;5:19-25. doi: 10.3762/bjnano.5.2.
The electronic and optical properties of semiconducting silicon nanotubes (SiNTs) are studied by means of the many-body Green's function method, i.e., GW approximation and Bethe-Salpeter equation. In these studied structures, i.e., (4,4), (6,6) and (10,0) SiNTs, self-energy effects are enhanced giving rise to large quasi-particle (QP) band gaps due to the confinement effect. The strong electron-electron (e-e) correlations broaden the band gaps of the studied SiNTs from 0.65, 0.28 and 0.05 eV at DFT level to 1.9, 1.22 and 0.79 eV at GW level. The Coulomb electron-hole (e-h) interactions significantly modify optical absorption properties obtained at noninteracting-particle level with the formation of bound excitons with considerable binding energies (of the order of 1 eV) assigned: the binding energies of the armchair (4,4), (6,6) and zigzag (10,0) SiNTs are 0.92, 1.1 and 0.6 eV, respectively. Results in this work are useful for understanding the physics and applications in silicon-based nanoscale device components.
采用多体格林函数方法，即 GW 近似和 Bethe-Salpeter 方程，研究了半导体硅纳米管（SiNTs）的电子和光学性质。在这些研究结构中，即（4,4）、（6,6）和（10,0）SiNTs，自能效应得到增强，由于限制效应，导致准粒子（QP）带隙增大。强电子-电子（e-e）相关性使研究的 SiNTs 的能带隙从 DFT 水平的 0.65、0.28 和 0.05 eV 拓宽至 GW 水平的 1.9、1.22 和 0.79 eV。库仑电子-空穴（e-h）相互作用显著改变了在非相互粒子水平下获得的光学吸收特性，形成了具有相当大结合能（约 1 eV）的束缚激子：扶手椅（4,4）、（6,6）和锯齿形（10,0）SiNTs 的结合能分别为 0.92、1.1 和 0.6 eV。这项工作的结果有助于理解基于硅的纳米级器件组件的物理和应用。
