Epitaxial Germanium Nanowires on GaAs Grown by Chemical Vapor Deposition

Abstract

We successfully synthesized epitaxial Ge nanowires on GaAs (100) and GaAs (111)B substrates by using Au-nanoparticle-catalyzed chemical vapor deposition. From an analysis of the inclined angles of the Ge nanowires to the substrate normal, we find that the epitaxial Ge nanowires grow along the directions regardless of the substrate’s orientation. This is in contrast with epitaxial Ge nanowires on Si and Ge substrates, which grow predominantly along the direction. In addition, tapering of the Ge nanowires is minimal even at relatively high growth temperatures due to the low surface mobility of the Ge adatoms on the GaAs surface.