Linjie Gao

Optimize the thermoelectric performance of CdO ceramics by doping Zn

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–x Zn x O systems at about 1000 K, which is comparable to the highest values reported for other n-type oxide TE materials.

Enhanced thermoelectric performance in Mg and Ca substituted CdO ceramics

We report a more than 50% enhancement in the thermoelectric figure of merit ZT of CdO ceramics via simultaneous substituting with Mg and Ca. The Mg and Ca substitution is found to greatly suppress both the electrical and the lattice thermal conductivities of CdO while maintaining a moderate power factor. Detailed mechanisms are proposed to explain the experimental results. A ZT value of 0.5 at about 1000 K has been achieved in the optimum substituted sample, which is the highest ZT ever reported among the n-type oxide thermoelectric materials in this temperature range.