title: Large Seebeck effect by charge-mobility engineering.
abstract: The Seebeck effect describes the generation of an electric potential in a conducting solid exposed to a temperature gradient. In most cases, it is dominated by an energy-dependent electronic density of states at the Fermi level, in line with the prevalent efforts towards superior thermoelectrics through the engineering of electronic structure. Here we demonstrate an alternative source for the Seebeck effect based on charge-carrier relaxation: a charge mobility that changes rapidly with temperature can result in a sizeable addition to the Seebeck coefficient. This new Seebeck source is demonstrated explicitly for Ni-doped CoSb3, where a marked mobility change occurs due to the crossover between two different charge-relaxation regimes. Our findings unveil the origin of pronounced features in the Seebeck coefficient of many other elusive materials characterized by a significant mobility mismatch. When utilized appropriately, this effect can also provide a novel route to the design of improved thermoelectric materials.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Peijie
authors.initials: P
authors.lastname: Sun
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Beipei
authors.initials: B
authors.lastname: Wei
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jiahao
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Solid State Physics, Vienna University of Technology, A-1040 Vienna, Austria.
authors.forename: Jan M
authors.initials: JM
authors.lastname: Tomczak
authors.affiliation: 1] Highly Correlated Matter Research Group, Department of Physics, University of Johannesburg, Auckland Park 2006, South Africa [2] Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Strydom
authors.affiliation: Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Søndergaard
authors.affiliation: Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Bo B
authors.initials: BB
authors.lastname: Iversen
authors.affiliation: 1] Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Steglich