Anomalous thermoelectricity of pure ZnO from 3D continuous ultrathin nanoshell structures

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Kisun Kim
  • Junyong Park
  • Seokkyoon Hong
  • Sun Hwa Park
  • Seong Gi Jeon
  • Changui Ahn
  • Jae Yong Song

Detail(s)

Original languageEnglish
Pages (from-to)3046-3052
Journal / PublicationNanoscale
Volume10
Issue number6
Online published2 Jan 2018
Publication statusPublished - 14 Feb 2018
Externally publishedYes

Abstract

ZnO is a potential thermoelectric material because of its non-toxicity, high thermal stability, and relatively high Seebeck coefficient (S) of metal oxides. However, the extremely low figure of merit (zT), which comes from a high thermal conductivity (κ) over 40 W m-1 K-1, limits the thermoelectric application of ZnO. In particular, below 500 K, ZnO exhibits a nearly negligible zT (<10-3), unless a dopant is incorporated into the crystal structure. Here, we propose a new strategy for achieving a reduced κ and a correspondingly increased zT of pure ZnO over a wide temperature range from 333 K to 723 K by forming an ∼72 nm thick, 3D continuous ultrathin nanoshell structure. The suppressed κ of the 3D ZnO film is ∼3.6 W m-1 K-1 at 333 K, which is ∼38 times lower than that of the blanket ZnO film (3.2 μm thick), which was set as a reference. The experimental zT of the 3D ZnO film is ∼0.017 at 333 K, which is the highest value among pure ZnO reported to date and is estimated to increase by ∼0.072 at 693 K according to the Debye-Callaway approach. Large-area (∼1 in2) fabrication of the 3D ZnO film with high structural uniformity allows the realization of an integrated thermoelectric device, which generates ∼60 mV at a temperature difference of 40 K along the in-plane direction.

Citation Format(s)

Anomalous thermoelectricity of pure ZnO from 3D continuous ultrathin nanoshell structures. / Kim, Kisun; Park, Junyong; Hong, Seokkyoon; Park, Sun Hwa; Jeon, Seong Gi; Ahn, Changui; Song, Jae Yong; Jeon, Seokwoo.

In: Nanoscale, Vol. 10, No. 6, 14.02.2018, p. 3046-3052.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review