Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons

The thermoelectric properties of zigzag graphene nanoribbons (ZGNRs) are sensitive to chemical modification. In this study, we employed density functional theory (DFT) combined with the nonequilibrium green’s function (NEGF) formalism to investigate the thermoelectric properties of a ZGNR system by...

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Autores principales:	Saeideh Ramezani Akbarabadi, Mojtaba Madadi Asl
Formato:	article
Lenguaje:	EN
Publicado:	Hindawi Limited 2021
Materias:	Physics QC1-999
Acceso en línea:	https://doaj.org/article/ed73824226704eb28ed45f4bee034f3b
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spelling	oai:doaj.org-article:ed73824226704eb28ed45f4bee034f3b2021-11-08T02:35:48ZImpurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons1687-812410.1155/2021/8110754https://doaj.org/article/ed73824226704eb28ed45f4bee034f3b2021-01-01T00:00:00Zhttp://dx.doi.org/10.1155/2021/8110754https://doaj.org/toc/1687-8124The thermoelectric properties of zigzag graphene nanoribbons (ZGNRs) are sensitive to chemical modification. In this study, we employed density functional theory (DFT) combined with the nonequilibrium green’s function (NEGF) formalism to investigate the thermoelectric properties of a ZGNR system by impurity substitution of single and double nitrogen (N) atoms into the edge of the nanoribbon. N-doping changes the electronic transmission probability near the Fermi energy and suppresses the phononic transmission. This results in a modified electrical conductance, thermal conductance, and thermopower. Ultimately, simultaneous increase of the thermopower and suppression of the electron and phonon contributions to the thermal conductance leads to the significant enhancement of the figure of merit in the perturbed (i.e., doped) system compared to the unperturbed (i.e., nondoped) system. Increasing the number of dopants not only changes the nature of transport and the sign of thermopower but also further suppresses the electron and phonon contributions to the thermal conductance, resulting in an enhanced thermoelectric figure of merit. Our results may be relevant for the development of ZGNR devices with enhanced thermoelectric efficiency.Saeideh Ramezani AkbarabadiMojtaba Madadi AslHindawi LimitedarticlePhysicsQC1-999ENAdvances in Condensed Matter Physics, Vol 2021 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Physics QC1-999
spellingShingle	Physics QC1-999 Saeideh Ramezani Akbarabadi Mojtaba Madadi Asl Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
description	The thermoelectric properties of zigzag graphene nanoribbons (ZGNRs) are sensitive to chemical modification. In this study, we employed density functional theory (DFT) combined with the nonequilibrium green’s function (NEGF) formalism to investigate the thermoelectric properties of a ZGNR system by impurity substitution of single and double nitrogen (N) atoms into the edge of the nanoribbon. N-doping changes the electronic transmission probability near the Fermi energy and suppresses the phononic transmission. This results in a modified electrical conductance, thermal conductance, and thermopower. Ultimately, simultaneous increase of the thermopower and suppression of the electron and phonon contributions to the thermal conductance leads to the significant enhancement of the figure of merit in the perturbed (i.e., doped) system compared to the unperturbed (i.e., nondoped) system. Increasing the number of dopants not only changes the nature of transport and the sign of thermopower but also further suppresses the electron and phonon contributions to the thermal conductance, resulting in an enhanced thermoelectric figure of merit. Our results may be relevant for the development of ZGNR devices with enhanced thermoelectric efficiency.
format	article
author	Saeideh Ramezani Akbarabadi Mojtaba Madadi Asl
author_facet	Saeideh Ramezani Akbarabadi Mojtaba Madadi Asl
author_sort	Saeideh Ramezani Akbarabadi
title	Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
title_short	Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
title_full	Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
title_fullStr	Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
title_full_unstemmed	Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons
title_sort	impurity substitution enhances thermoelectric figure of merit in zigzag graphene nanoribbons
publisher	Hindawi Limited
publishDate	2021
url	https://doaj.org/article/ed73824226704eb28ed45f4bee034f3b
work_keys_str_mv	AT saeidehramezaniakbarabadi impuritysubstitutionenhancesthermoelectricfigureofmeritinzigzaggraphenenanoribbons AT mojtabamadadiasl impuritysubstitutionenhancesthermoelectricfigureofmeritinzigzaggraphenenanoribbons
_version_	1718443243485528064

Impurity Substitution Enhances Thermoelectric Figure of Merit in Zigzag Graphene Nanoribbons

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