title: High temperature Z-meter setup for characterizing thermoelectric material under large temperature gradient.
abstract: To properly estimate a thermoelectric material's performance, one should be able to characterize a single thermoelectric (TE) element with a large temperature gradient. In this work, we present an experimental setup including a Z-meter that can heat the sample to a very high temperature of 1200 °C in vacuum. The Z-meter can simultaneously measure all three thermoelectric parameters (Seebeck coefficient, thermal conductivity, and electrical conductivity), as well as measure the generated power and the efficiency for a single TE leg. Furthermore, this measurement of power conversion efficiency is used to generate a measure of the material's ZT. An in situ metallurgical bond was used to achieve low thermal (0.05 Kcm(2)/W) and electrical (3 mΩ) contact parasitics. An integrated strain gauge ensures reproducible thermal contact. At high temperature (>600 K), radiative heat transfer is modeled and the instrument is optimized to suppress the systematic error to below 7%. The TE parameters and ZT for a bulk-sample (Bi(2)Te(3)) and a thin-film sample (ErAs:InGaAlAs) with a large temperature gradient (ΔT ∼ 200 K) have been measured and are within 3%-7% of the independently measured values.
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, USA. ramatya@mit.edu
authors.forename: R
authors.initials: R
authors.lastname: Amatya
authors.forename: P M
authors.initials: PM
authors.lastname: Mayer
authors.forename: R J
authors.initials: RJ
authors.lastname: Ram