title: Periodically changing morphology of the growth interface in Si, Ge, and GaP nanowires.
abstract: Nanowire growth in the standard <111> direction is assumed to occur at a planar catalyst-nanowire interface, but recent reports contradict this picture. Here we show that a nonplanar growth interface is, in fact, a general phenomenon. Both III-V and group IV nanowires show a distinct region at the trijunction with a different orientation whose size oscillates during growth, synchronized with step flow. We develop an explicit model for this structure that agrees well with experiment and shows that the oscillations provide a direct visualization of catalyst supersaturation. We discuss the implications for wire growth and structure.
authors.affiliation: School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Wen
authors.forename: J
authors.initials: J
authors.lastname: Tersoff
authors.forename: K
authors.initials: K
authors.lastname: Hillerich
authors.forename: M C
authors.initials: MC
authors.lastname: Reuter
authors.forename: J H
authors.initials: JH
authors.lastname: Park
authors.forename: S
authors.initials: S
authors.lastname: Kodambaka
authors.forename: E A
authors.initials: EA
authors.lastname: Stach
authors.forename: F M
authors.initials: FM
authors.lastname: Ross