Growth and characterization of GaAs/In_xGa_1-xAs/GaAs axial nanowire heterostructures with symmetrical heterointerfaces

We report on the Au-assisted vapour-liquid-solid (VLS) growth of GaAs/In_xGa_1-xAs/GaAs (0.2 ≤ x ≤ 1) axial double-heterostructure nanowires on GaAs (111) B substrates via metal-organic chemical vapor deposition (MOCVD) technique. The influence of indium content in Au particle on the morphology of nanowires is investigated systematically. A short period of pre-introduced indium precursor before the growth of In_xGa_1-xAs segment, coupled with a group III precursor interruption, is conducive to obtaining symmetrical heterointerfaces as well as the desired In/Ga ratio in the In_xGa_1-xAs section. The nanowire morphology, such as kinking and tapering, are thought to be related to the In composition in the catalyst alloy as well as the VLS growth mechanism.