title: Surface Hydrogen Enables Subeutectic Vapor-Liquid-Solid Semiconductor Nanowire Growth.
abstract: Vapor-liquid-solid nanowire growth below the bulk metal-semiconductor eutectic temperature is known for several systems; however, the fundamental processes that govern this behavior are poorly understood. Here, we show that hydrogen atoms adsorbed on the Ge nanowire sidewall enable AuGe catalyst supercooling and control Au transport. Our approach combines in situ infrared spectroscopy to directly and quantitatively determine hydrogen atom coverage with a "regrowth" step that allows catalyst phase to be determined with ex situ electron microscopy. Maintenance of a supercooled catalyst with only hydrogen radical delivery confirms the centrality of sidewall chemistry. This work underscores the importance of the nanowire sidewall and its chemistry on catalyst state, identifies new methods to regulate catalyst composition, and provides synthetic strategies for subeutectic growth in other nanowire systems.
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Saujan V
authors.initials: SV
authors.lastname: Sivaram
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Ho Yee
authors.initials: HY
authors.lastname: Hui
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, Bellaterra, Barcelona, Catalonia 08193, Spain.
authors.forename: María
authors.initials: M
authors.lastname: de la Mata
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, Bellaterra, Barcelona, Catalonia 08193, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Filler
keywords: germanium; hydrogen; semiconductor nanowire; vapor−liquid−solid mechanism