High thermoelectric performance of dually doped ZnO ceramics

Michitaka Ohtaki, Kazuhiko Araki, Kiyoshi Yamamoto

    Research output: Contribution to journalArticlepeer-review

    333 Citations (Scopus)


    A marked improvement in the thermoelectric performance of dense ZnO ceramics is achieved by employing a third element as a co-dopant with Al. Dual doping of ZnO with Al and Ga results in a drastic decrease in the thermal conductivity of the oxide, while the decrease in the electrical conductivity is relatively small. With the aid of a significant enhancement in the thermopower, the dually doped oxide shows thermoelectric figure of merit values, ZT, values of 0.47 at 1000 K and 0.65 at 1247 K at the composition Zn 0.96Al 0.02Ga 0.02O. These results appear to be the highest ZT values so far reported for bulk n-type oxides. Microscopic observation of the samples reveals a granular texture in the densely sintered oxide matrix, suggesting that considerable reduction of the thermal conductivity while maintaining high electrical conductivity could be achieved by such a bulk nanocomposite structure in the samples.

    Original languageEnglish
    Pages (from-to)1234-1238
    Number of pages5
    JournalJournal of Electronic Materials
    Issue number7
    Publication statusPublished - Jul 2009

    All Science Journal Classification (ASJC) codes

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Electrical and Electronic Engineering
    • Materials Chemistry


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