Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA.
Nat Commun. 2013;4:1339. doi: 10.1038/ncomms2350.
The electrical properties of nanostructures are extremely sensitive to their surface condition. In very thin two-dimensional crystalline-semiconductor sheets, termed nanomembranes, the influence of the bulk is diminished, and the electrical conductance becomes exquisitely responsive to the structure of the surface and the type and density of defects there. Its understanding therefore requires a precise knowledge of the surface condition. Here we report measurements, using nanomembranes, that demonstrate direct charge transport through the π* band of the clean reconstructed Si(001) surface. We determine the charge carrier mobility in this band. These measurements, performed in ultra-high vacuum to create a truly clean surface, lay the foundation for a quantitative understanding of the role of extended or localized surface states, created by surface structure, defects or adsorbed atoms/molecules, in modifying charge transport through semiconductor nanostructures.
纳米结构的电学性质对其表面状态极其敏感。在非常薄的二维晶态-半导体片中，称为纳米膜，体相的影响减弱，电导率对外表结构、表面的缺陷类型和密度变得极其敏感。因此，对其的理解需要对表面状态有精确的认识。在此，我们通过纳米膜的测量，报告了证明通过清洁重构 Si(001)表面的π*带的直接电荷输运的实验结果。我们确定了这个能带中的载流子迁移率。这些在超高真空下进行的测量结果，为定量理解由表面结构、缺陷或吸附原子/分子产生的扩展或局域表面态在通过半导体纳米结构的电荷输运中所起的作用奠定了基础。
