title: Direct imaging of the atomic structure inside a nanowire by scanning tunnelling microscopy.
abstract: Semiconductor nanowires are expected to be important components in future nano-electronics and photonics. Already a wide range of applications has been realized, such as high-performance field-effect transistors, bio/chemical sensors, diode logics and single-nanowire lasers. As nanowires have small cross-sections and large surface-to-bulk ratios, their properties can be significantly influenced by individual atomic-scale structural features, and they can have properties or even atomic arrangements with no bulk counterparts. Hence, experimental methods capable of directly addressing the atomic-scale structure of nanowires are highly desirable. One such method is scanning tunnelling microscopy (STM), which, by direct imaging of the atomic and electronic structure of surfaces has revolutionized the perception of nanoscale objects and low-dimensional systems. Here we demonstrate how combining STM with an embedding scheme allows us to image the interior of semiconductor nanowires with atomic resolution. Defect structures such as planar twin segments and single-atom impurities are imaged inside a GaAs nanowire. Further, we image an intriguing GaAs nanowire that is separated into two distinct nanocrystallites along the growth direction of the wire.
authors.affiliation: Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden. anders.mikkelsen@sljus.lu.se
authors.forename: Anders
authors.initials: A
authors.lastname: Mikkelsen
authors.forename: Niklas
authors.initials: N
authors.lastname: Sköld
authors.forename: Lassana
authors.initials: L
authors.lastname: Ouattara
authors.forename: Magnus
authors.initials: M
authors.lastname: Borgström
authors.forename: Jesper N
authors.initials: JN
authors.lastname: Andersen
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
authors.forename: Werner
authors.initials: W
authors.lastname: Seifert
authors.forename: Edvin
authors.initials: E
authors.lastname: Lundgren
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D003461:Crystallography / Q000379:methods; D004559:Electric Wiring; D005708:Gallium / Q000737:chemistry*; D008420:Manufactured Materials; D008422:Materials Testing / Q000379:methods*; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D001152:Arsenicals; C043055:gallium arsenide; D005708:Gallium