A Pathway to Type-I Band Alignment in Ge/Si Core-Shell Nanowires

Title
A Pathway to Type-I Band Alignment in Ge/Si Core-Shell Nanowires
Authors
Jongseob Kim이정훈Ki-Ha Hong
Keywords
type-I/II transition; quantum well; quantum confinement; strain; density functional theory
Issue Date
2013-01
Publisher
Journal of Physical Chemistry Letters
Citation
VOL 4, NO 1, 121-126
Abstract
We investigate the electronic band structures of Ge/Si core–shell nanowires (CSNWs) and devise a way to realize the electron quantum well at Ge core atoms with first-principles calculations. We reveal that the electronic band engineering by the quantum confinement and the lattice strain can induce the type-I/II band alignment transition, and the resulting type-I band alignment generates the electron quantum well in Ge/Si CSNWs. We also find that the type-I/II transition in Ge/Si CSNWs is highly related to the direct to indirect band gap transition through the analysis of charge density and band structures. In terms of the quantum confinement, for [100] and [111] directional Ge/Si CSNWs, the type-I/II transition can be obtained by decreasing the diameters, whereas a [110] directional CSNW preserves the type-II band alignment even at diameters as small as 1 nm. By applying a compressive strain on [110] CSNWs, the type-I band alignment can be formed. Our results suggest that Ge/Si CSNWs can have the type-I band alignment characteristics by the band structure engineering, which enables both n-type and p-type quantum-well transistors to be fabricated using Ge/Si CSNWs for high-speed logic applications.
URI
http://pubs.kist.re.kr/handle/201004/45053
ISSN
19487185
Appears in Collections:
KIST Publication > Article
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE