Work

Tuning thermoelectric properties of graphene/boron nitride heterostructures

Year: 2015

Type: article

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.

Source: Nanotechnology

DOI: 10.1088/0957-4484/26/47/475401

Authors: Laith A Algharagholy, Qusiy Al-Galiby, Haider A Marhoon, Hatef Sadeghi, Hayder M Abduljalil, Colin J Lambert

Institutions: University of Al-Qadisiyah, University of Sumer, Lancaster University, University of Babylon

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: green

Funders: Ministère de l'Education Nationale, de l'Enseignement Superieur et de la Recherche, Engineering and Physical Sciences Research Council, Sixth Framework Programme