title: Characterization of Ambipolar GaSb/InAs Core-Shell Nanowires by Thermovoltage Measurements.
abstract: In semiconductor heterostructures with a type II band alignment, such as GaSb-InAs, conduction can be tuned from electron- to hole-dominated using an electrostatic gate. However, traditional conductance measurements give no direct information on the carrier type, and thus limit the ability to distinguish transport effects originating from the two materials. Here, we employ thermovoltage measurements to GaSb/InAs core-shell nanowires, and reliably identify the dominant carrier type at room temperature as well as in the quantum transport regime at 4.2 K, even in cases where the conductance measurement does not allow for such a distinction. In addition, we show that theoretical modeling using the conductance data as input can reproduce the measured thermovoltage under the assumption that electron and hole states shift differently in energy with the applied gate voltage.
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.|‡School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Jan G
authors.initials: JG
authors.lastname: Gluschke
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Leijnse
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.
authors.forename: Bahram
authors.initials: B
authors.lastname: Ganjipour
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.|§Center for Analysis and Synthesis, Lund University, Box 124, S-22100 Lund, Sweden.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Dick
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.
authors.forename: Heiner
authors.initials: H
authors.lastname: Linke
authors.affiliation: †Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.
authors.forename: Claes
authors.initials: C
authors.lastname: Thelander
keywords: GaSb/InAs; ambipolar; core/shell; field effect; nanowires; thermovoltage