High thermoelectric properties of p-type BiCuSeO co-doped with Ca2+ and Ba2+

In this work, we prepare Ca2+ and Ba2+ co-doped BiCuSeO using a solid-state reaction, followed by spark plasma sintering. Ca2+/Ba2+ co-doping significantly increases the electrical conductivity through the increased hole concentration. In addition to the increased power factor, Ca2+/Ba2+ co-doping reduces the phonon thermal conductivity through grain refinement, increased porosity, and mass and strain field fluctuations. The combination of the largest power factor and the low phonon thermal conductivity for Bi0.80Ca0.10Ba0.10CuSeO yields the largest dimensionless figure-of-merit (ZT). The ZT of Bi0.80Ca0.10Ba0.10CuSeO (0.60) at 600 degrees C is two times larger than that of the undoped BiCuSeO (0.30) at 600 degrees C. We systematically discuss the effect of the Ca2+/Ba2+ co-doping on the thermoelectric properties of BiCuSeO oxyselenide. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

By co-doping with Ca2+ and Ba2+, the electrical conductivity of BiCuSeO is significantly increased while the phonon thermal conductivity is reduced. This combination leads to a significant improvement in thermoelectric performance.