title: Structure and morphology in diffusion-driven growth of nanowires: the case of ZnTe.
abstract: Gold-catalyzed ZnTe nanowires were grown at low temperature by molecular beam epitaxy on a ZnTe(111) B buffer layer, under different II/VI flux ratios, including with CdTe insertions. High-resolution electron microscopy and energy-dispersive X-ray spectroscopy (EDX) gave information about the crystal structure, polarity, and growth mechanisms. We observe, under stoichiometric conditions, the simultaneous presence of zinc-blende and wurtzite nanowires spread homogeneously on the same sample. Wurtzite nanowires are cylinder-shaped with a pyramidal-structured base. Zinc-blende nanowires are cone-shaped with a crater at their base. Both nanowires and substrate show a Te-ended polarity. Te-rich conditions favor zinc-blende nanowires, while Zn-rich suppress nanowire growth. Using a diffusion-driven growth model, we present a criterion for the existence of a crater or a pyramid at the base of the nanowires. The difference in nanowire morphology indicates lateral growth only for zinc-blende nanowires. The role of the direct impinging flux on the nanowire's sidewall is discussed.
authors.affiliation: Inst. NEEL, Univ. Grenoble Alpes , F-38042 Grenoble, France , and Inst. NEEL, CNRS , F-38042 Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Rueda-Fonseca
authors.forename: E
authors.initials: E
authors.lastname: Bellet-Amalric
authors.forename: R
authors.initials: R
authors.lastname: Vigliaturo
authors.forename: M
authors.initials: M
authors.lastname: den Hertog
authors.forename: Y
authors.initials: Y
authors.lastname: Genuist
authors.forename: R
authors.initials: R
authors.lastname: André
authors.forename: E
authors.initials: E
authors.lastname: Robin
authors.forename: A
authors.initials: A
authors.lastname: Artioli
authors.forename: P
authors.initials: P
authors.lastname: Stepanov
authors.forename: D
authors.initials: D
authors.lastname: Ferrand
authors.forename: K
authors.initials: K
authors.lastname: Kheng
authors.forename: S
authors.initials: S
authors.lastname: Tatarenko
authors.forename: J
authors.initials: J
authors.lastname: Cibert