Structural polytypism and residual strain in GaAs nanowires grown on Si(111) probed by single-nanowire X-ray diffraction

Abstract

The structural composition, phase arrangement and residual strain of individual GaAs nanowires (NWs) grown on Si(111) have been investigated using NW-resolved high-resolution X-ray diffraction employing a focused synchrotron beam. It is found that even neighbouring NWs grown on the same sample under the same growth conditions differ significantly in their phase structure, most of them exhibiting small wurtzite segments embedded between larger zincblende sections. Moreover, using structurally sensitive Bragg reflections, residual strain is observed in the zincblende sections of the NWs, likely caused by an incomplete relaxation at the substrate interface.