Tuning thermoelectric properties of graphene/boron nitride heterostructures

Algharagholy, Laith A. and Al-Galiby, Qusiy and Marhoon, Haider A. and Sadeghi, Hatef and Abduljalil, Hayder M. and Lambert, Colin J. (2015) Tuning thermoelectric properties of graphene/boron nitride heterostructures. Nanotechnology, 26 (47). ISSN 0957-4484

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Abstract

Using density functional theory combined with a Green's function scattering approach, we examine the thermoelectric properties of hetero-nanoribbons formed from alternating lengths of graphene and boron nitride. In such structures, the boron nitride acts as a tunnel barrier, which weakly couples states in the graphene, to form mini-bands. In un-doped nanoribbons, the mini bands are symmetrically positioned relative to the Fermi energy and do not enhance thermoelectric performance significantly. In contrast, when the ribbons are doped by electron donating or electron accepting adsorbates, the thermopower S and electronic figure of merit are enhanced and either positive or negative thermopowers can be obtained. In the most favourable case, doping with the electron donor tetrathiafulvalene increases the room-temperature thermopower to -284 μv K(-1) and doping by the electron acceptor tetracyanoethylene increases S to 210 μv K(-1). After including both electron and phonon contributions to the thermal conductance, figures of merit ZT up to of order 0.9 are obtained.

Item Type: Journal Article
Journal or Publication Title: Nanotechnology
Additional Information: This is an author-created, un-copyedited version of an article accepted for publication/published in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/0957-4484/26/47/475401
Uncontrolled Keywords: /dk/atira/pure/subjectarea/asjc/2200/2208
Subjects:
Departments: Faculty of Science and Technology > Physics
ID Code: 76648
Deposited By: ep_importer_pure
Deposited On: 17 Nov 2015 09:13
Refereed?: Yes
Published?: Published
Last Modified: 21 Feb 2020 02:43
URI: https://eprints.lancs.ac.uk/id/eprint/76648

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