Optimize the thermoelectric performance of CdO ceramics by doping Zn**Project supported by the National Natural Science Foundation of China (Grant No. 51372064), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2014201176 and E2017201209), the Outstanding Doctoral Cultivation Project of Hebei University (Grant No. YB201502), and the Hebei Province Universities Science and Technology Program funded by the Hebei Provincial

Abstract

The thermoelectric performance of CdO ceramics was enhanced by simultaneously optimizing the electrical and thermal transport properties via a small amount of Zn doping (≤ 3%). The introduction of Zn can obviously increase the electrical conductivity of CdO due to the simultaneous increase of carrier concentration and mobility, and eventually results in an improvement in power factor. Zn doping is also effective in suppressing the thermal conductivity of CdO because of stronger phonon scatterings from point defects, Zn-riched second phase, and grain boundaries. A best ZT of about 0.45 has been achieved in the Cd1–xZnxO systems at about 1000 K, which is comparable to the highest values reported for other n-type oxide TE materials.