Au-catalysed free-standing wurtzite structured InAs nanosheets grown by molecular beam epitaxy

In this study, we report the growth of free-standing InAs nanosheets using Au catalysts in molecular beam epitaxy. Detailed structural characterizations suggest that wurtzite structured InAs nanosheets, with features of extensive {1120} surfaces, grown along the < 1102 > direction and adopted {0001} nanosheet/catalyst interfaces, are initiated from wurtzite structured [0001] nanowires as the inclined epitaxial growth due to relatively higher In concentrations in Au catalysts, and grown from these inclined nanostructures through catalyst-induced axial growth and their enhanced lateral growth under the high growth temperature. Based on the facts that the nanosheets contain large low energy {1120} surfaces and {0001} nanosheet/catalyst interfaces, the growth of our nanosheets is a thermodynamically driven process. This study provides new insights into fabricating free-standing Ⅲ-Ⅴ nanosheets for their applications in future nanoscale devices.