Electronic Properties of Strained Si/Ge Core-Shell Nanowires

Autor:	Peng, Xihong, Logan, Paul
Rok vydání:	2010
Předmět:	Physics - Computational Physics Condensed Matter - Mesoscale and Nanoscale Physics
Zdroj:	Applied Physics Letters 96, 143119 (2010)
Druh dokumentu:	Working Paper
DOI:	10.1063/1.3389495
Popis:	We investigated the electronic properties of strained Si/Ge core-shell nanowires along the [110] direction using first principles calculations based on density-functional theory. The diameter of the studied core-shell wire is up to 5 nm. We found the band gap of the core-shell wire is smaller than that of both pure Si and Ge wires with the same diameter. This reduced band gap is ascribed to the intrinsic strain between Ge and Si layers, which partially counters the quantum confinement effect. The external strain is further applied to the nanowires for tuning the band structure and band gap. By applying sufficient tensile strain, we found the band gap of Si-core/Ge-shell nanowire with diameter larger than ~3 nm experiences a transition from direct to indirect gap. Comment: 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1010.1555 Zobrazit plný text záznamu View this record from Arxiv