Control of the crystal structure of InAs nanowires by tuning contributions of adatomdiffusion

Abstract

The dependence of crystal structure on contributions of adatom diffusion (ADD) andprecursor direct impingement (DIM) was investigated for vapor–liquid–solid growth of InAsnanowires (NWs). The ADD contributions from the sidewalls and substrate surface can bechanged by using GaAs NWs of different length as the basis for growing InAs NWs. We foundthat pure zinc-blende structure is favored when DIM contributions dominate. Moreover,without changing the NW diameter or growth parameters (such as temperature orV/III ratio), a transition from zinc-blende to wurtzite structure can be realized by increasing theADD contributions. A nucleation model is proposed in which ADD and DIMcontributions play different roles in determining the location and phase of the nucleus.