title: Phase segregation in AlInP shells on GaAs nanowires.
abstract: We have studied morphology and phase segregation of AlInP shells on GaAs nanowires. Photoluminescence measurements on single core-shell nanowires indicated variations in the shell composition, and phase segregation was confirmed by cross-sectional scanning transmission electron microscopy on 30 nm thin slices of the wires. It was discovered that Al-rich domains form in the <112> directions where two {110} shell facets meet during growth. We propose that the mechanism behind this phase segregation is a variation in the chemical potential along the circumference of the nanowire together with a difference in diffusion lengths for the different growth species. From the morphology of the core and the shell, we conclude that the side facet growth is temperature dependent forming {112}facets at low growth temperature and {110} facets at high growth temperature.
authors.affiliation: Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Sköld
authors.forename: Jakob B
authors.initials: JB
authors.lastname: Wagner
authors.forename: Gunnel
authors.initials: G
authors.lastname: Karlsson
authors.forename: Tania
authors.initials: T
authors.lastname: Hernán
authors.forename: Werner
authors.initials: W
authors.lastname: Seifert
authors.forename: Mats-Erik
authors.initials: ME
authors.lastname: Pistol
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson