Growth and characterization of InAs1-xSbx nanowires and InAs(Sb)/GaSb core-shell heterostructures

Heidi Potts, Martin Friedl, Gözde Tütüncüoglu, Federico Matteini and Anna Fontcuberta i Morral

Laboratory for Semiconductor Materials, EPF Lausanne, Switzerland

InAs and InSb nanowires have received considerable attention for electronic transport experiments due to high spin-orbit coupling, large g-factor, and high electron mobility. InAs1-xSbx nanowires are expected to offer new opportunities based on the tunable band gap of the ternary alloy. We study the growth of InAs(Sb) nanowires without a foreign catalyst on GaAs(111)B substrates using molecular beam epitaxy. The nanowires are analyzed with high resolution transmission electron microscopy. Our results show that InAs nanowires are polytypic with a high density of stacking faults. Incorporation of antimony dramatically improves the nanowire crystal structure, and pure zinc blende InAs1-xSbx nanowires are obtained for an antimony content above 25%. The electrical properties of InAs(Sb) nanowires are studied using field-effect measurements. We further investigate the growth of InAs(Sb)/GaSb core-shell heterostructure nanowires. The heterostructure nanowires are expected to show interesting transport properties due to the peculiar broken band alignment of InAs and GaSb.