Metal-sown selective area growth of high crystalline quality InAsSb nanowires and networks by molecular-beam epitaxy

Abstract

Scalable in-plane InAsSb nanowires and networks have attracted intense research interest in optoelectronics and quantum computation. However, the poor crystalline quality of InAsSb nanowires and networks limits the development of high-performance nanodevices. Here, we report the growth of high crystalline quality InAsSb nanowires and networks on patterned Ge substrates by molecular-beam epitaxy. We find that high crystalline quality InAsSb nanowires can be successfully achieved by the conventional selective area growth route. But continuous nanowires and networks cannot be obtained by this growth manner. To overcome this problem, a metal-sown selective area growth route is developed. By precisely tuning the growth parameters, the well-aligned InAsSb nanowires and networks have been successfully fabricated. It is determined that the morphologies of nanowires and networks are dependent on the local growth rate and the V/III ratio, and the V/III ratio has an obvious effect on the polarity of nanowires and networks. Detailed structural studies confirm that these well-faceted nanowires are pure zinc blende single crystals, and there is a strict epitaxial relationship between the nanowire and the substrate. The energy dispersive spectroscopy analyses indicate that the Sb content is evenly distributed along the in-plane direction and has an obvious gradient along the out-of-plane direction. The successful fabrication of high crystalline quality InAsSb nanowires and networks provides new opportunities for exploring potential optoelectronic applications.