Understanding the 3D structure of GaAs⟨111⟩B nanowires

The effects of lamellar twinning in epitaxial particle-assisted GaAs < 111 > B nanowires are investigated in an extensive high resolution electron microscopy (HRTEM) study of the low index zones < 100 >, < 110 >, < 111 > and < 112 >. As these directions are non-parallel to the (111) twin planes we find that the twin segments exhibit two different zone axes as a consequence of twinning. In the first three cases the alternative zones were found to be < 122 > < 114 > and < 115 >. These findings are supported by a comparison of experimental HRTEM images and multi-slice simulations along with fast Fourier transform mapping. From the appearance of non-overlapping regions we conclude that the nanowires are bound by {111} facets only. The twin formation and the development of the stable side facets are discussed.