title: Subsurface imaging of coupled carrier transport in GaAs/AlGaAs core-shell nanowires.
abstract: We demonstrate spatial probing of carrier transport within GaAs/AlGaAs core-shell nanowires with nanometer lateral resolution and subsurface sensitivity by energy-variable electron beam induced current imaging. Carrier drift that evolves with applied electric field is distinguished from a coupled drift-diffusion length. Along with simulation of injected electron trajectories, combining beam energy tuning with precise positioning for selective probing of core and shell reveals axial position- and bias-dependent differences in carrier type and transport along parallel conduction channels. These results indicate how analysis of transport within heterostructured nanomaterials is no longer limited to nonlocal or surface measurements.
authors.affiliation: Department of Materials Science and Engineering and ∥Department of Physics, Drexel University , 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Guannan
authors.initials: G
authors.lastname: Chen
authors.forename: Terrence
authors.initials: T
authors.lastname: McGuckin
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hawley
authors.forename: Eric M
authors.initials: EM
authors.lastname: Gallo
authors.forename: Paola
authors.initials: P
authors.lastname: Prete
authors.forename: Ilio
authors.initials: I
authors.lastname: Miccoli
authors.forename: Nico
authors.initials: N
authors.lastname: Lovergine
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Spanier
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D004583:Electrons; D005708:Gallium / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*
chemical_list: D005708:Gallium; D000535:Aluminum
keywords: Electron beam induced current (EBIC); core−shell nanowire; heterostructured nanowire; scanning probe microscopy; subsurface imaging