Print Email Facebook Twitter Geometrically Enhanced Thermoelectric Effects in Graphene Nanoconstrictions Title Geometrically Enhanced Thermoelectric Effects in Graphene Nanoconstrictions Author Harzheim, Achim (University of Oxford) Spiece, Jean (Lancaster University) Evangeli, Charalambos (University of Oxford; Lancaster University) McCann, Edward (Lancaster University) Falko, Vladimir (The University of Manchester) Sheng, Yuewen (University of Oxford) Warner, Jamie H. (University of Oxford) Briggs, G. Andrew D. (University of Oxford) Mol, Jan A. (University of Oxford) Gehring, P. (TU Delft QN/van der Zant Lab; University of Oxford; Kavli institute of nanoscience Delft) Kolosov, Oleg V. (Lancaster University) Date 2018 Abstract The influence of nanostructuring and quantum confinement on the thermoelectric properties of materials has been extensively studied. While this has made possible multiple breakthroughs in the achievable figure of merit, classical confinement, and its effect on the local Seebeck coefficient has mostly been neglected, as has the Peltier effect in general due to the complexity of measuring small temperature gradients locally. Here we report that reducing the width of a graphene channel to 100 nm changes the Seebeck coefficient by orders of magnitude. Using a scanning thermal microscope allows us to probe the local temperature of electrically contacted graphene two-terminal devices or to locally heat the sample. We show that constrictions in mono- and bilayer graphene facilitate a spatially correlated gradient in the Seebeck and Peltier coefficient, as evidenced by the pronounced thermovoltage Vth and heating/cooling response TPeltier, respectively. This geometry dependent effect, which has not been reported previously in 2D materials, has important implications for measurements of patterned nanostructures in graphene and points to novel solutions for effective thermal management in electronic graphene devices or concepts for single material thermocouples. Subject graphene nanostructuresPeltierscanning thermal microscopySeebeckThermoelectrics To reference this document use: http://resolver.tudelft.nl/uuid:f6aa3da3-27d6-400b-a3d6-b760a352f5d1 DOI https://doi.org/10.1021/acs.nanolett.8b03406 ISSN 1530-6984 Source Nano Letters: a journal dedicated to nanoscience and nanotechnology, 7719-7725 Part of collection Institutional Repository Document type journal article Rights © 2018 Achim Harzheim, Jean Spiece, Charalambos Evangeli, Edward McCann, Vladimir Falko, Yuewen Sheng, Jamie H. Warner, G. Andrew D. Briggs, Jan A. Mol, P. Gehring, Oleg V. Kolosov Files PDF acs.nanolett.8b03406.pdf 2.55 MB Close viewer /islandora/object/uuid:f6aa3da3-27d6-400b-a3d6-b760a352f5d1/datastream/OBJ/view