Single-Crystalline Hexagonal Silicon–Germanium

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• 作者：Håkon Ikaros T. Hauge ; Sonia Conesa-Boj ; Marcel A. Verheijen ; Sebastian KoellingErik P. A. M. Bakkers
• 刊名：Nano Letters
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：17
• 期：1
• 页码：85-90
• 全文大小：396K
• ISSN：1530-6992

文摘

Group IV materials with the hexagonal diamond crystal structure have been predicted to exhibit promising optical and electronic properties. In particular, hexagonal silicon–germanium (Sib>1–xb>Geb>xb>) should be characterized by a tunable direct band gap with implications ranging from Si-based light-emitting diodes to lasers and quantum dots for single photon emitters. Here we demonstrate the feasibility of high-quality defect-free and wafer-scale hexagonal Sib>1–xb>Geb>xb> growth with precise control of the alloy composition and layer thickness. This is achieved by transferring the hexagonal phase from a GaP/Si core/shell nanowire template, the same method successfully employed by us to realize hexagonal Si. We determine the optimal growth conditions in order to achieve single-crystalline layer-by-layer Sib>1–xb>Geb>xb> growth in the preferred stoichiometry region. Our results pave the way for exploiting the novel properties of hexagonal Sib>1–xb>Geb>xb> alloys in technological applications.