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Title: Improvement of thermoelectric properties induced by uniquely ordered lattice field in Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array

In this study, it was found that uniquely ordered lattice field favors transport of carriers but hinder that of phonons. The n-Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array film was successfully achieved by a simple ion beam assisted deposition technique. This oriented pillar array structure is clear with pillar diameter of about 30 nm, exhibiting a uniquely ordered lattice field. The properties of the ordered Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array were greatly enhanced in comparison with those of the ordinary film. The Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array with a thermoelectric dimensionless figure-of-merit ZT=1.28 was obtained at room temperature. The in-plane transport mechanisms of the ordered pillar array and the ordinary structures, lattice field model, are proposed and investigated. The specially ordered lattice field is the main reason for the properties enhancement observed in the Bi{sub 2}Se{sub 0.5}Te{sub 2.5} film. Introduction of such ordered lattice field into TE films is therefore a very promising approach. - Graphical abstract: In this study, it was found that uniquely ordered lattice field favors transport of carriers but hinder that of phonons. The Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array film with a thermoelectric dimensionless figure-of-merit ZT=1.28 was obtained at room temperature. The in-plane transportmore » mechanisms of the ordered pillar array and the ordinary structures, the lattice field model, are proposed and investigated. The specially ordered lattice field is the main reason for the properties enhancement observed in the Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array. Introduction of such uniquely ordered lattice field into TE films is therefore a very promising approach. In (a) TEM and (b) HRTEM images of the ordered Bi{sub 2}Se{sub 0.5}Te{sub 2.5} column array. - Highlights: • Uniquely ordered Bi{sub 2}Se{sub 0.5}Te{sub 2.5} pillar array was achieved by an IBAD method. • The pillar array with an ordered lattice field exhibits attractive TE property. • The transport mechanism of such ordered pillar array is proposed and investigated. • Introduction of such ordered lattice field into film is a very promising approach.« less
Authors:
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Publication Date:
OSTI Identifier:
22334285
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 215; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DEPOSITION; FILMS; ION BEAMS; THERMOELECTRIC PROPERTIES; TRANSMISSION ELECTRON MICROSCOPY