InSb Nanowire Networks Grown by Groove-Guided Selective Area Epitaxy on Ge Substrates

InSb is an excellent material for studying topological quantum computing, infrared optoelectronics, and spintronics. Controllable growth of high-quality, large-scale InSb nanowire networks is the basis for these applications. However, the selective growth window and the epitaxial growth window of InSb nanowire networks do not overlap when they are grown by molecular-beam epitaxy. So far, the controlled growth of high-quality large-scale InSb nanowire networks still remains a challenge. Here, a groove-guided selective area growth technique is proposed for InSb nanowire network growth on Ge substrates by molecular-beam epitaxy. Different from the traditional planar selective epitaxial growth technology, in the proposed method, the material is epitaxially grown at the grooves of the substrate, and the selective growth is achieved by utilizing the atomic diffusion of the epitaxial material on the substrate surface: Selective growth is achieved without using any masks. The InSb nanowire networks grown by this manner have continuous morphology with flat top facets, and they are high-quality zinc-blende crystals and exhibit strong spin-orbit interaction. Due to good repeatability and scalability, the work provides a new solution to grow high-quality wafer-scale InSb nanowire networks on Ge substrates.