High-temperature oxide thermoelectrics

TL;DR

This paper evaluates the high-temperature thermoelectric properties of transition metal oxides, revealing a nearly constant power factor across doping levels and proposing oxide thermoelectric generators with high thermopower.

Contribution

It introduces a method to evaluate power factors in oxides at high temperatures and proposes oxide thermoelectric generators with high thermopower based on these findings.

Findings

Power factor is nearly independent of doping in transition metal oxides.

High thermopower (>300 μV/K) can be achieved with high power factors.

Proposed oxide thermoelectric generators with high efficiency.

Abstract

We have evaluated the power factor of transition metal oxides at high temperatures using the Heikes formula and the Ioffe-Regel conductivity. The evaluated power factor is found to be nearly independent of carrier concentration in a wide range of doping, and well explains the experimental data for cobalt oxides. This suggests that the same power factor can be obtained with a thermopower larger than $2k_B/e$, and also suggests a reasonably high value of the dimensionless figure of merit $ZT$. We propose an oxide thermoelectric power generator by using materials having a thermopower larger than 300 $\mu$V/K.