GaAs/AlGaAs nanowire heterostructures studied by scanning tunneling microscopy.
We directly image the interior of GaAs/AlGaAs axial and radial nanowire heterostructures with atomic-scale resolution using scanning tunneling microscopy. We show that formation of monolayer sharp and smooth axial interfaces are possible even by vapor-phase epitaxy. However, we also find that instability of the ternary alloys formed in the Au seed fundamentally limits axial heterostructure control, inducing large segment asymmetries. We study radial core-shell nanowires, imaging even ultrathin submonolayer shells. We demonstrate how large twinning-induced morphological defects at the wire surfaces can be removed, ensuring the formation of wires with atomically flat sides.
Ouattara
Lassana
L
Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden.
Mikkelsen
Anders
A
Sköld
Niklas
N
Eriksson
Jessica
J
Knaapen
Thijs
T
Cavar
Elizabeta
E
Seifert
Werner
W
Samuelson
Lars
L
Lundgren
Edvin
E
D000535:Aluminum / Q000737:chemistry*; D001152:Arsenicals / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D005708:Gallium / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
D001152:Arsenicals; D046911:Macromolecular Substances; C043055:gallium arsenide; D005708:Gallium; D000535:Aluminum