In-situ X-ray analysis of misfit strain and curvature of bent polytypic GaAs-In(x)Ga(1-x)As core-shell nanowires

Abstract

Misfit strain in core-shell nanowires can be elastically released by nanowire bending in case of asymmetric shell growth around the nanowire core. In this work, we investigate the bending of GaAs nanowires during the asymmetric overgrowth by an In(x)Ga(1-x)As shell caused by avoiding substrate rotation. We observe that the nanowire bending direction depends on the nature of the substrate's oxide layer, demonstrated by Si substrates covered by native and thermal oxide layers. Further, we follow the bending evolution by time-resolved in-situ X-ray diffraction measurements during the deposition of the asymmetric shell. The XRD measurements give insight into the temporal development of the strain as well as the bending evolution in the core-shell nanowire.

References in corpus (5)

• Up to 40 % reduction of the GaAs band gap energy via strain engineering in core/shell nanowires
• Strain in Semiconductor Core-Shell Nanowires
• A portable MBE system for in situ X-Ray investigations at synchrotron beamlines
• Surface preparation and patterning by nano imprint lithography for the selective area growth of GaAs nanowires on Si(111)
• Influence of the source arrangement on shell growth around GaN nanowires in molecular beam epitaxy