High temperature thermopower of sol-gel processed Zn1-x-y Al (x) Me (y) O (Me: Ga, In)


KILINÇ E., DEMİRCİ S. , UYSAL F., ÇELİK E., KURT H.

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, vol.28, no.16, pp.11769-11778, 2017 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 16
  • Publication Date: 2017
  • Doi Number: 10.1007/s10854-017-6982-7
  • Title of Journal : JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
  • Page Numbers: pp.11769-11778

Abstract

In this study, dually doped samples of Zn1-x-y Al (x) Me (y) O (Me: Ga, In) were prepared by sol-gel process followed by hot isostatic pressing for high temperature thermoelectric applications. Material characterizations were performed with differential thermal analysis-thermogravimetry, Fourier transform infrared spectroscopy and X-ray diffraction on the target phases. Successful doping of the samples was confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray analysis. Thermopower values of the samples are found to be relatively high in analogy to semiconducting behavior in which negative values indicate electrons are the dominant charge carriers (n-type). Substitution of Zn2+ by Ga3+ and In3+ for Zn1-x-y Al (x) Me (y) O (Me: Ga, In) increases electron concentration in the samples and thereby decreases the thermopower values compared to Zn0.98Al0.02O. Considering the absolute values, In doped samples have higher thermopower (alpha (max) = -162 A mu V/K at 585 A degrees C for Zn0.96Al0.02In0.02O) compared to the Ga doped sample. Al and In dually doped Zn0.96Al0.02In0.02O could be considered as a promising n-type thermoelectric material for high temperature applications.