title: Phase selection enabled formation of abrupt axial heterojunctions in branched oxide nanowires.
abstract: Rational synthesis of nanowires via the vapor-liquid-solid (VLS) mechanism with compositional and structural controls is vitally important for fabricating functional nanodevices from bottom up. Here, we show that branched indium tin oxide nanowires can be in situ seeded in vapor transport growth using tailored Au-Cu alloys as catalyst. Furthermore, we demonstrate that VLS synthesis gives unprecedented freedom to navigate the ternary In-Sn-O phase diagram, and a rare and bulk-unstable cubic phase can be selectively stabilized in nanowires. The stabilized cubic fluorite phase possesses an unusual almost equimolar concentration of In and Sn, forming a defect-free epitaxial interface with the conventional bixbyite phase of tin-doped indium oxide that is the most employed transparent conducting oxide. This rational methodology of selecting phases and making abrupt axial heterojunctions in nanowires presents advantages over the conventional synthesis routes, promising novel composition-modulated nanomaterials.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Oleg I
authors.initials: OI
authors.lastname: Lebedev
authors.forename: Stuart
authors.initials: S
authors.lastname: Turner
authors.forename: Yong Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Yun Hao
authors.initials: YH
authors.lastname: Lu
authors.forename: Yuan Ping
authors.initials: YP
authors.lastname: Feng
authors.forename: Philippe
authors.initials: P
authors.lastname: Boullay
authors.forename: Wilfrid
authors.initials: W
authors.lastname: Prellier
authors.forename: Gustaaf
authors.initials: G
authors.lastname: van Tendeloo
authors.forename: Tom
authors.initials: T
authors.lastname: Wu
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D044367:Phase Transition; D012666:Semiconductors; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D010087:Oxides; D017971:Tin Compounds; C109984:indium tin oxide