title: Position controlled nanowire growth through Au nanoparticles synthesized by galvanic reaction.
abstract: Semiconductor nanowires have emerged as promising materials for fundamental studies in quantum-confined systems and applications in nanophotonics and electronics, but major challenges remain in controlling nanowire properties, including their position and size. Here, we report a simple and efficient electrochemical process that combines galvanic reaction and electron-beam lithography to selectively synthesize gold nanoparticles that are consequently used for the growth of ordered GaAs nanowire arrays with pre-defined diameter and position. Size and density control of gold nanoparticles is achieved on non-patterned GaAs substrates by changing the reaction time and concentration of Au(3 + ) ions during the galvanic reaction. Spontaneous formation of localized etch pits is observed when the galvanic reaction is constrained to lithography-defined substrate regions, which confines small-diameter Au nanoparticles during the high temperature growth of GaAs nanowire arrays and enables epitaxial growth of well-ordered nanowire structures.
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Chun-Hao
authors.initials: CH
authors.lastname: Tseng
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Tambe
authors.forename: Sung K
authors.initials: SK
authors.lastname: Lim
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Smith
authors.forename: Silvija
authors.initials: S
authors.lastname: Gradecak
mesh_terms: D003460:Crystallization / Q000379:methods*; D004595:Electroplating / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006046:Gold