abstract
This work aims to explore zirconium as a possible dopant to promote thermoelectric performance in bulk ZnO-based materials, both within the single-doping concept and on simultaneous co-doping with aluminum. At 1100-1223 K mixed-doped samples demonstrated around similar to 2.3 times increase in ZT as compared to single-doped materials, reaching similar to 0.12. The simultaneous presence of aluminum and zirconium imposes a synergistic effect on electrical properties provided by their mutual effects on the solubility in ZnO crystal lattice, while also allowing a moderate decrease of the thermal conductivity due to phonon scattering effects. At 1173 K the power factor of mixed-doped Zn0.994Al0.003Zr0.003O was 2.2-2.5 times higher than for single-doped materials. Stability tests of the prepared materials under prospective operation conditions indicated that the gradual increase in both resistivity and Seebeck coefficient in mixed-doped compositions with time may partially compensate each other to maintain a relatively high power factor.
keywords
AL-DOPED ZNO; ELECTRICAL-PROPERTIES; TRANSPORT-PROPERTIES; THIN-FILMS; POWER; MORPHOLOGY; CERAMICS; PROGRESS; LATTICE
subject category
Materials Science
authors
Zakharchuk, KV; Tobaldi, DM; Xiao, XX; Xie, WJ; Mikhalev, SM; Martins, JF; Frade, JR; Weidenkaff, A; Kovalevsky, AV
our authors
Andrei Kavaleuski
Principal Researcher
David Maria Tobaldi
Researcher
Jorge Ribeiro Frade
Retired Professor
Kiryl Zakharchuk
PhD Student
Sergey Mikhalev
Post-Doc FellowshipGroups
G3 - Electrochemical Materials, Interfaces and Coatings
G4 - Renewable Materials and Circular Economy
acknowledgements
This work was supported by the FCT, including individual grant IF/00302/2012, project CICECO-Aveiro Institute of Materials (ref. UID/CTM/50011/2013), project of bilateral cooperation between FCT and DAAD (Germany) and the project POCI-01-0145-FEDER-031875, financed by COMPETE 2020 Program and operational Program POCI in its FEDER/FNR component, and the Foundation for Science and Technology, in its State Budget component (OE), and when applicable co-financed by FEDER under the PT2020 Partnership Agreement.