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Published January 12, 2015 | Published + Erratum
Journal Article Open

Band gap estimation from temperature dependent Seebeck measurement — Deviations from the 2e|S|_(max)T_(max) relation


In characterizing thermoelectric materials, electrical and thermal transport measurements are often used to estimate electronic band structure properties such as the effective mass and band gap. The Goldsmid-Sharp band gap, Eg  = 2e|S|_(max)T_(max), is a tool widely employed to estimate the band gap from temperature dependent Seebeck coefficient measurements. However, significant deviations of more than a factor of two are now known to occur. We find that this is when either the majority-to-minority weighted mobility ratio (A) becomes very different from 1.0 or as the band gap (Eg) becomes significantly smaller than 10 kBT. For narrow gaps (Eg  ≲ 6 kBT), the Maxwell-Boltzmann statistics applied by Goldsmid-Sharp break down and Fermi-Dirac statistics are required. We generate a chart that can be used to quickly estimate the expected correction to the Goldsmid-Sharp band gap depending on A and S_(max); however, additional errors can occur for S < 150 μV/K due to degenerate behavior.

Additional Information

© 2015 AIP Publishing LLC. Received 19 November 2014; accepted 2 January 2015; published online 15 January 2015. The authors would like to acknowledge funding from The Materials Project: supported by Department of Energy's Basic Energy Sciences program under Grant No. EDCBEE and DOE Contract No. DE-AC02-05CH11231.

Attached Files

Published - 1.4905922.pdf

Erratum - 1.4951680.pdf


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August 20, 2023
August 20, 2023