A simplified model explaining the formation of InAs nanowires on GaAs nanomembranes


Gold-free GaAs nanomembranes have proven ideal templates for further growth of in-plane III-V nanowires. Recently, it has been demonstrated that high quality InAs nanowires with a low defect density can be obtained on top of GaAs nanomembranes by molecular beam epitaxy in wafer-scale approach and provide an excellent platform for future investigations into one-dimensional transport and quantum computation. Here, we develop a model to explain why InAs NWs form spontaneously on the top ridges of GaAs nanomembranes and not elsewhere. We speculate that the driving force for this growth mechanism is the free energy minimization including the elastic and surface energy contributions.