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arXiv · 1512.04235

Network theory for inhomogeneous thermoelectrics

Sebastian Angst·Dietrich E. Wolf
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Abstract

The Onsager-de Groot-Callen transport theory, implemented as a network model, is used to simulate the transient Harman method, which is widely used experimentally to determine all thermoelectric transport coefficients in a single measurement setup. It is shown that this method systematically overestimates the Seebeck coefficient for samples composed of two different materials. As a consequence, the figure of merit is also overestimated, if the thermal coupling of the measurement setup to the environment is weak. For a mixture of metal and semiconductor particles near metal percolation the figure of merit obtained by the Harman method is more than 100 \% too large. For a correct interpretation of the experimental data, information on composition and microstructure of the sample are indispensable.

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Sebastian Angst, Dietrich E. Wolf. 2015-12-14. Network theory for inhomogeneous thermoelectrics. https://doi.org/10.1088/1367-2630%2F18%2F4%2F043004

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