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arXiv · 1401.3030

Wiedemann-Franz Relation and Thermal-transistor Effect in Suspended Graphene

S. Yigen·A. R. Champagne
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Abstract

We extract experimentally the electronic thermal conductivity, $K_{e}$, in suspended graphene which we dope using a back-gate electrode. We make use of two-point dc electron transport at low bias voltages and intermediate temperatures (50 - 160 K), where the electron and lattice temperatures are decoupled. The thermal conductivity is proportional to the charge conductivity times the temperature, confirming that the Wiedemann-Franz relation is obeyed in suspended graphene. We extract an estimate of the Lorenz coefficient as 1.1 to 1.7 $\times 10^{-8}$ W $Ω$K$^{-2}$. $K_e$ shows a transistor effect and can be tuned with the back-gate by more than a factor of 2 as the charge carrier density ranges from $\approx$ 0.5 to 1.8 $\times 10^{11}$cm$^{-2}$.

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S. Yigen, A. R. Champagne. 2014-01-13. Wiedemann-Franz Relation and Thermal-transistor Effect in Suspended Graphene. https://doi.org/10.1021/nl403967z

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