Power factor enhancement of thermoelectric oxide composites for high temperature applications

Yurdakul, Emre Burak
In this work, we report a simultaneous increase in Seebeck coefficient and electrical conductivity, that results in increasing power factor, of Ca3Co4O9 (C-349) ceramic by forming a composite system together with another promising oxyselenide; BiCuSeO (BCSO). Pristine C-349 and BCSO were synthesized using sol-gel and solid-state reaction methods, respectively and mixed by several ball-milling steps. We observed a remarkable increase in the power factor of, approximately 41% higher than the power factor of pristine C-349 at 900 K. The addition of BCSO phase results in slight decrease in carrier concentration and at the same time creates more porous structure. Both consequences have a positive impact on Seebeck coefficient. The reason for enhancement in electrical conductivity is related with high increase in hole mobility without significant decrease in carrier concentration. This study might inspire other researchers to explore the new concepts of developing high power factor thermoelectric (TE) materials. To our best knowledge, this is the first study on the TE properties of C-349/BCSO composites.
Citation Formats
E. B. Yurdakul, “Power factor enhancement of thermoelectric oxide composites for high temperature applications,” M.S. - Master of Science, Middle East Technical University, 2018.