High-temperature ZT of InGaAlAs Thin Films with Embedded ErAs Nanoparticles

ORAL

Abstract

We have measured the thermoelectric (TE) figure-of-merit (ZT) of InGaAlAs thin films with embedded ErAs nanoparticles over a wide temperature range (300K - 650K). This material system is currently being explored for use in power generation applications such as waste heat recovery. A novel high-speed measurement system was developed to measure the ZT of thin films of thicknesses on the order of 1um with a transient thermal signal resolution of 200ns at temperatures up to 900K. In order to resolve the intrinsic ZT of thin-film materials, TE devices were fabricated to minimize electrical and thermal parasitics and differential measurement was employed on TE devices of varying film thicknesses. The improvement in ZT of the material with ErAs nanoparticles embedded in the semiconductor matrix is verified throughout the temperature range. The increase in TE ZT is found to be mainly due to the reduction in material thermal conductivity due to phonon scattering by the ErAs nanoparticles.

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Authors

  • Rajeev Singh

    Electrical Engineering Department, University of California, Santa Cruz, California 95064, Electrical Engineering Department, University of California, Santa Cruz

  • Zhixi Bian

    Electrical Engineering Department, University of California, Santa Cruz, California 95064, Electrical Engineering Department, University of California, Santa Cruz, University of California, Santa Cruz

  • Younes Ezzahri

    Electrical Engineering Department, University of California, Santa Cruz

  • Ali Shakouri

    Electrical Engineering Department, University of California, Santa Cruz, California 95064, University of California,Santa Cruz, Electrical Engineering Department, University of California, Santa Cruz, University of California, Santa Cruz, University of California Santa Cruz

  • Gehong Zeng

    Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, Department of Electrical and Computer Engineering, University of California, Santa Barbara, University of California, Santa Barbara

  • John Bowers

    Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, Department of Electrical and Computer Engineering, University of California, Santa Barbara

  • Joshua Zide

    Materials Department, University of California, Santa Barbara

  • Arthur Gossard

    Materials Department, University of California, Santa Barbara, Materials Dept., UCSB, UC Santa Barbara, Univ. California, Santa Barbara, University of California, Santa Barbara, UCSB