Low thermal conductivity and enhanced thermoelectric performance of nanostructured Al-doped ZnTe

Ankam Bhaskar, Yi Hsuan Pai, Wei Ming Wu, Ching Lin Chang, Chia-Jyi Liu

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Nanostructured Zn1-xAlxTe (0≤x≤0.15) samples have been fabricated using hydrothermal synthesis and evacuating-and-encapsulating sintering. Thermoelectric properties are measured at 300-600 K. The thermopower of all the samples is positive, indicating that the predominant carriers are holes over the entire temperature range. The hole concentration increases with increasing Al3+ content. Based on the charge neutrality, the hole concentration is expected to decrease upon Al doping. However, the x-ray absorption spectroscopy indicates the electrons transfer from Zn 4s to Te 5d states upon Al doping, which might explain that the increase of hole concentration upon partial Al3+ substitution of Zn2+. Using Slack's model for estimating the lattice thermal conductivity, the Grüneisen parameter at 300 K is found to increase with Al doping content. The highest power factor (1.52 μW m-1 K-2) and highest dimensionless figure of merit (0.075) are attained at 575 K for Zn0.85Al0.15Te, representing an improvement of about 508% and 851% with respect to the nondoped ZnTe at the same temperature. These results suggest that aluminum is an effective doping element for improving the thermoelectric properties of ZnTe.

Original languageEnglish
Pages (from-to)1070-1076
Number of pages7
JournalCeramics International
Volume42
Issue number1
DOIs
Publication statusPublished - 2016 Jan 1

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Hole concentration
Thermal conductivity
Doping (additives)
Hydrothermal synthesis
Thermoelectric power
Aluminum
Absorption spectroscopy
Chemical elements
Substitution reactions
Sintering
X rays
Temperature
Electrons

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

Bhaskar, Ankam ; Pai, Yi Hsuan ; Wu, Wei Ming ; Chang, Ching Lin ; Liu, Chia-Jyi. / Low thermal conductivity and enhanced thermoelectric performance of nanostructured Al-doped ZnTe. In: Ceramics International. 2016 ; Vol. 42, No. 1. pp. 1070-1076.
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Low thermal conductivity and enhanced thermoelectric performance of nanostructured Al-doped ZnTe. / Bhaskar, Ankam; Pai, Yi Hsuan; Wu, Wei Ming; Chang, Ching Lin; Liu, Chia-Jyi.

In: Ceramics International, Vol. 42, No. 1, 01.01.2016, p. 1070-1076.

Research output: Contribution to journalArticle

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