3D Atomic-Scale Insights into Anisotropic Core-Shell-Structured InGaAs Nanowires Grown by Metal-Organic Chemical Vapor Deposition

Jiangtao Qu; Sichao Du; Tim Burgess; Changhong Wang; Xiangyuan Cui; Qiang Gao; Weichao Wang; Hark Hoe Tan; Hui Liu; Chennupati Jagadish; Yingjie Zhang; Hansheng Chen; Mansoor Khan; Simon Ringer; Rongkun Zheng

doi:10.1002/adma.201701888

3D Atomic-Scale Insights into Anisotropic Core-Shell-Structured InGaAs Nanowires Grown by Metal-Organic Chemical Vapor Deposition

Adv Mater. 2017 Aug;29(31). doi: 10.1002/adma.201701888. Epub 2017 Jun 19.

Authors

Affiliations

¹ School of Physics and the Australian Institute for Nanoscale Science and Technology, The University of Sydney, 2006, Sydney, Australia.
² Department of Electronic Materials Engineering, The Australian National University, 2601, Canberra, Australia.
³ Department of Electronic Science and Engineering, Nankai University, 300350, Tianjing, China.
⁴ Australian Centre for Microscopy & Microanalysis and Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, 2006, Sydney, Australia.
⁵ Australian Nuclear Science and Technology Organisation, 2001, Sydney, Australia.

PMID: 28628253
DOI: 10.1002/adma.201701888

Abstract

III-V ternary InGaAs nanowires have great potential for electronic and optoelectronic device applications; however, the 3D structure and chemistry at the atomic-scale inside the nanowires remain unclear, which hinders tailoring the nanowires for specific applications. Here, atom probe tomography is used in conjunction with a first-principles simulation to investigate the 3D structure and chemistry of InGaAs nanowires, and reveals i) the nanowires form a spontaneous core-shell structure with a Ga-enriched core and an In-enriched shell, due to different growth mechanisms in the axial and lateral directions; ii) the shape of the core evolves from hexagon into Reuleaux triangle and grows larger, which results from In outward and Ga inward interdiffusion occurring at the core-shell interface; and iii) the irregular hexagonal shell manifests an anisotropic growth rate on {112}A and {112}B facets. Accordingly, a model in terms of the core-shell shape and chemistry evolution is proposed, which provides fresh insights into the growth of these nanowires.

Keywords: InGaAs nanowires; atom probe tomography; core-shell structures; epitaxy growth; gold catalysts.