Comparison of Thermoelectric Transport Measurement Techniques Using n-type PbSe

We compare high-temperature thermoelectric transport measurements at two different institutes using different setups. The material studied is n-type PbSe doped with Cl. The measurements at the Ioffe Institute used a steady-state design which allowed all three properties to be measured simultaneously from bar-shaped samples. Those at Caltech have used Van der Pauw geometry for resistivity, an oscillation method for the Seebeck coefficient, and a laser flash technique for thermal conductivity. The results for each individual property show differences around 10% in some cases, while the evaluation of overall zT for the three samples with different doping levels is mostly below 10%. The steady-state method at the Ioffe Institute was able to measure thermal conductivity at high temperature as accurately as the laser flash method. In general, great caution is needed for any setup in order to accurately measure high-temperature transport properties and hence zT.