Single-Crystalline Hexagonal Silicon–Germanium

详细信息    查看全文

• 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 (Si_1–xGe_x) 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 Si_1–xGe_x 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 Si_1–xGe_x growth in the preferred stoichiometry region. Our results pave the way for exploiting the novel properties of hexagonal Si_1–xGe_x alloys in technological applications.