Band structures, nanowire theoretical modeling

Nanowire systems have attracted a great deal of attention recently due to their technological potential They are of fundamental interest because they exhibit unique quantum confinement effects. In this article, advances in the fabrication of nanowires via template-assisted and laser-assisted approaches are reviewed. The structure and characteristics of different nanowire systems are discussed. To understand and predict the unusual properties of nanowires, we have developed a generalized theoretical model for the band structure of these onedimensional systems. A unique semimetal-semiconductor transition that occurs in bismuth nanowires is described. Transport measurements on bismuth and antimony nanowires illustrate that these novel materials are very different from their bulk counterparts. A transport... 

This chapter summarizes the main theoretical approaches to model the porous silicon electronic band structure, comparing effective mass theory, semiempirical, and first-principles methods. In order to model its complex porous morphology, supercell, nanowire, and nanocrystal approaches are widely used. In particular, calculations of strain, doping, and surface chemistry effects on the band structure are discussed. Finally, the combined use of ab initio and tight-binding approaches to predict the band structure and properties of electronic devices based on porous silicon is put forward. 

---