Crystal-phase control of GaAs–GaAsSb core–shell/axial nanowire heterostructures by a two-step growth method

Abstract

The growth of III–Sb nanowires with controlled wurtzite and zinc-blende structures is essential for tailoring their fundamental properties and in turn potential applications. However, most studies of III–Sb nanowires have shown that they adopt the zinc-blende structure, so that the growth of wurtzite structured III–Sb nanowires needs to be explored. In this study, both wurtzite and zinc-blende structured GaAs–GaAsSb core–shell nanowire heterostructures and axial heterostructures were grown by tuning the crystal structure of nanowire cores and varying the Sb flux. Our aberration-corrected electron microscopy investigations suggest that the nanowire shells maintained the same crystal structure as their nanowire cores. Besides, it was found that the axial–lateral GaAs–GaAaSb heterostructures were grown with increasing the Sb flux, due to the increased Sb supersaturation at the catalyst–nanowire interface. This study provides an avenue for growing III–Sb nanowires with desired crystal structures in order to secure different properties.