Kim, Jongseob Lee, Jung Hoon Hong, Ki-Ha 2024-01-20T13:04:21Z 2024-01-20T13:04:21Z 2021-09-01 2013-01 1948-7185 https://pubs.kist.re.kr/handle/201004/128488 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. English American Chemical Society A Pathway to Type-I Band Alignment in Ge/Si Core-Shell Nanowires Article 10.1021/jz301975v 1 The Journal of Physical Chemistry Letters, v.4, no.1, pp.121 - 126 The Journal of Physical Chemistry Letters 4 1 121 126 N scie scopus 000313142000036 2-s2.0-84872172657 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Atomic, Molecular & Chemical Chemistry Science & Technology - Other Topics Materials Science Physics Article SILICON NANOWIRES TRANSISTORS CHANNEL HETEROSTRUCTURES MOSFETS type-I/II transition quantum well quantum confinement strain density functional theory