title: Semiconductor nanowires and nanotubes: effects of size and surface-to-volume ratio.
abstract: The electronic properties of semiconductor (SiC, GaN, BN, ZnO, ZnS, and CdS) nanowires and nanotubes were investigated using first-principles calculations based on density functional theory and generalized gradient approximation. Different size or surface-to-volume ratio dependences were found for the II-VI (ZnO, ZnS, and CdS) and IV-IV (SiC) and III-V (GaN and BN) nanostructures. For SiC, GaN, and BN nanostructures, the band gap decreases with the increase of the surface-to-volume ratio or the reduction of the diameter, while for ZnO, ZnS, and CdS nanostructures, the band gap increases with the increase of surface-to-volume ratio or the reduction of the diameter. The mechanism is attributed to the competition between the interaction from dangling p-like and sigma states and the quantum confinement effect.
authors.affiliation: Department of Physics, National University of Singapore, Singapore 117542, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Pan
authors.forename: Yuan Ping
authors.initials: YP
authors.lastname: Feng
mesh_terms: D002104:Cadmium / Q000737:chemistry; D003460:Crystallization; D004563:Electrochemistry; D004581:Electronics; D008968:Molecular Conformation; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry; D053770:Nanowires; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D002104:Cadmium