Disorder-free localization around the conduction band edge of crossing and kinked silicon nanowires

Abstract

We explore ballistic regime quantum transport characteristics of oxide-embedded crossing and kinked silicon nanowires (NWs) within a large-scale empirical pseudopotential electronic structure framework, coupled to the Kubo-Greenwood transport analysis. A real-space wave function study is undertaken and the outcomes are interpreted together with the findings of ballistic transport calculations. This reveals that ballistic transport edge lies tens to hundreds of millielectron volts above the lowest unoccupied molecular orbital, with a substantial number of localized states appearing in between, as well as above the former. We show that these localized states are not due to the oxide interface, but rather core silicon-derived. They manifest the wave nature of electrons brought to foreground by the reflections originating from NW junctions and bends. Hence, we show that the crossings and kinks of even ultraclean Si NWs possess a conduction band tail without a recourse to atomistic disorder.

Published version, 7 pages, 9 figures

References in corpus (4)

• Bandstructure Effects in Silicon Nanowire Electron Transport
• Atomistic Origin of Urbach Tails in Amorphous Silicon
• Interband, intraband and excited-state direct photon absorption of silicon and germanium nanocrystals embedded in a wide band-gap lattice
• Networks of silicon nanowires: a large-scale atomistic electronic structure analysis

Cited by in corpus (1)

• Electron ground state $g$ factor in embedded InGaAs quantum dots: An atomistic study