Understanding the 3D structure of \mathrm {GaAs\langle 111\rangle B} nanowires

Abstract

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>, <-1-10>, <1-1-1> and <1-1-2>. As these directions are non-parallel to the (-1-1-1) 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 <1-2-2> <11-4> and <11-5>. 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