Peelaers H, Durgun E, Partoens B, Bilc D I, Ghosez Ph, Van de Walle C G, Peeters F M
Materials Department, University of California, Santa Barbara, CA 93106-5050, United States of America. Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.
J Phys Condens Matter. 2017 Mar 8;29(9):095303. doi: 10.1088/1361-648X/aa5768. Epub 2017 Jan 6.
The effect of B and P dopants on the band structure of Si nanowires is studied using electronic structure calculations based on density functional theory. At low concentrations a dispersionless band is formed, clearly distinguishable from the valence and conduction bands. Although this band is evidently induced by the dopant impurity, it turns out to have purely Si character. These results can be rigorously analyzed in the framework of effective mass theory. In the process we resolve some common misconceptions about the physics of hydrogenic shallow impurities, which can be more clearly elucidated in the case of nanowires than would be possible for bulk Si. We also show the importance of correctly describing the effect of dielectric confinement, which is not included in traditional electronic structure calculations, by comparing the obtained results with those of GW calculations.
基于密度泛函理论的电子结构计算方法，研究了硼（B）和磷（P）掺杂对硅纳米线能带结构的影响。在低掺杂浓度下，形成了一条无色散带，与价带和导带明显区分。虽然这条能带显然是由掺杂杂质诱导产生的，但结果表明它具有纯粹的硅特性。这些结果可以在有效质量理论的框架内进行严格分析。在此过程中，我们澄清了一些关于类氢浅杂质物理性质的常见误解，相较于体硅，这些误解在纳米线的情况下能得到更清晰的阐释。通过将所得结果与GW计算结果进行比较，我们还展示了正确描述介电限制效应的重要性，而传统电子结构计算中并未包含这一效应。
