Growth of semiconductor nanowires by molecular beam epitaxy

In this chapter, we offer many different angles to assess the implications and the role (past, present and future) of molecular beam epitaxy (MBE) for the synthesis of semiconductor nanowires. We provide a bird's eye review of the state of the art relative to bare growth, reporting which materials have been primarily chosen for nanowire synthesis, and discuss the fundamental classification based on different growth mechanisms (metal-induced, self-induced and metal-free). We also analyse in-depth the existing models developed to describe the nanowire growth process. Further, we characterise the general features of MBE-made nanowires in terms of structural complexity and optical properties. The significant import of MBE towards the realisation of nanowires with controllable doping, multiple crystal phases and axial or radial heterostructures is emphasised. Finally, a number of nanowire-based devices are presented, focussing mostly on their level of maturity and future potential.