title: Influence of surface states and size effects on the Seebeck coefficient and electrical resistance of Bi1-xSbxnanowire arrays.
abstract: The Seebeck coefficient and electrical resistance of Bi1-xSbxnanowire arrays electrodeposited in etched ion-track membranes have been investigated as a function of wire diameter (40-750 nm) and composition (0 ≤ x ≤ 1). The experimental data reveal a non-monotonic dependence between thermopower and wire diameter for three different compositions. Thus, the thermopower values decrease with decreasing wire diameter, exhibiting a minimum around ∼60 nm. This non-monotonic dependence of the Seebeck coefficient is attributed to the interplay of surface and bulk states. On the one hand, the metallic properties of the surface states can contribute to decreasing the thermopower of the nanostructure with increasing surface-to-volume ratio. On the other hand, for wires thinner than ∼60 nm, the relative increase of the thermopower can be tentatively attributed to the presence of quantum-size effects on both surface and bulk states. These measurements contribute to a better understanding of the interplay between bulk and surface states in nanostructures, and indicate that the decrease of Seebeck coefficient with decreasing diameter caused by the presence of surfaces states can possibly be overcome for even thinner nanowires.
authors.affiliation: Material Research Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, Planckstrasse. 1, D-64291 Darmstadt, Germany. m.cassinelli@gsi.de m.e.toimilmolares@gsi.de and Technische Universität Darmstadt, Material- und Geowissenschaften, Petersenstrasse 23, D-64287 Darmstadt, Germany.
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-1679-5090
authors.initials: M
authors.lastname: Cassinelli
authors.affiliation: Material Research Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, Planckstrasse. 1, D-64291 Darmstadt, Germany. m.cassinelli@gsi.de m.e.toimilmolares@gsi.de.
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.affiliation: Material Research Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, Planckstrasse. 1, D-64291 Darmstadt, Germany. m.cassinelli@gsi.de m.e.toimilmolares@gsi.de.
authors.forename: K-O
authors.initials: KO
authors.lastname: Voss
authors.affiliation: Material Research Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, Planckstrasse. 1, D-64291 Darmstadt, Germany. m.cassinelli@gsi.de m.e.toimilmolares@gsi.de and Technische Universität Darmstadt, Material- und Geowissenschaften, Petersenstrasse 23, D-64287 Darmstadt, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Trautmann
authors.affiliation: University of Applied Sciences Wiesbaden, Am Brückweg 26, 65428, Rüsselsheim, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Völklein
authors.affiliation: Institute of Applied Physics, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany and IBM Research Zurich, Sauemerstrasse 4, 8803 Rueschlikon, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Gooth
authors.affiliation: Institute of Applied Physics, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Nielsch
authors.affiliation: Material Research Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, Planckstrasse. 1, D-64291 Darmstadt, Germany. m.cassinelli@gsi.de m.e.toimilmolares@gsi.de.
authors.forename: M E
authors.initials: ME
authors.lastname: Toimil-Molares