Phase analysis and thermoelectric properties of Zn_1−<i>x</i>M<i>_x</i>O (M= Al, Ga) samples

Abstract

Thermoelectric oxides have been regarded as promising materials for power generation especially at high temperature. Among them, ZnO systems have been reported as useful n ‐type thermoelectrics because of high Seebeck coefficients and electrical conductivities at high temperature. In this study, we investigated polycrystalline ZnO systems doped with different donor ions Al 3+ and Ga 3+ . We investigated reasons of different solution limits and secondary phases and microstructures between these two donor‐doped cases. Thermoelectric properties also showed different tendency between Al 3+ ‐ and Ga 3+ ‐doped ZnO systems because of their different structural properties. As a result, a maximum power factor value 9.18 × 10 −4 W/mK 2 at 1050 K was obtained in Zn 0.98 Ga 0.02 O composition. Copyright © 2012 John Wiley &amp; Sons, Ltd.