title: Polarity-Driven Quasi-3-Fold Composition Symmetry of Self-Catalyzed III-V-V Ternary Core-Shell Nanowires.
abstract: A quasi-3-fold composition symmetry has for the first time been observed in self-catalyzed III-V-V core-shell nanowires. In GaAsP nanowires, phosphorus-rich sheets on radial {110} planes originating at the corners of the hexagonal core were observed. In a cross section, they appear as six radial P-rich bands that originate at the six outer corners of the hexagonal core, with three of them higher in P content along ⟨112⟩A direction and others along ⟨112⟩B, forming a quasi-3-fold composition symmetry. We propose that these P-rich bands are caused by a curvature-induced high surface chemical potential at the small corner facets, which drives As adatoms away more efficiently than P adatoms. Moreover, their polarity related P content difference can be explained by the different adatom bonding energies at these polar corner facets. These results provide important information on the further development of shell growth in the self-catalyzed core-shell NW structure and, hence, device structure for multicomponent material systems.
authors.affiliation: †Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, United Kingdom.
authors.forename: Yunyan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: ‡Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: †Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, United Kingdom.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: §Gasp Solar ApS, Gregersensvej 7, Taastrup DK-2630, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Aagesen
authors.affiliation: §Gasp Solar ApS, Gregersensvej 7, Taastrup DK-2630, Denmark.|∥Center for Quantum Devices, Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
authors.forename: Jeppe V
authors.initials: JV
authors.lastname: Holm
authors.affiliation: ‡Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Beanland
authors.affiliation: ‡Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ward
authors.affiliation: †Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, United Kingdom.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Liu
keywords: GaAsP nanowire; III−V−V; P-rich bands; compositional phase segregation; core−shell; polarity; quasi-3-fold symmetry; self-catalyzed; ternary