Details
| Original language | English |
|---|---|
| Pages (from-to) | 1660-1664 |
| Number of pages | 5 |
| Journal | Nano letters |
| Volume | 17 |
| Issue number | 3 |
| Early online date | 20 Feb 2017 |
| Publication status | Published - 8 Mar 2017 |
| Externally published | Yes |
Abstract
We present a theoretical study of electronic and thermal transport in polycrystalline heterostructures combining graphene (G) and hexagonal boron nitride (hBN) grains of varying size and distribution. By increasing the hBN grain density from a few percent to 100%, the system evolves from a good conductor to an insulator, with the mobility dropping by orders of magnitude and the sheet resistance reaching the MΩ regime. The Seebeck coefficient is suppressed above 40% mixing, while the thermal conductivity of polycrystalline hBN is found to be on the order of 30-120 Wm-1 K-1. These results, agreeing with available experimental data, provide guidelines for tuning G-hBN properties in the context of two-dimensional materials engineering. In particular, while we proved that both electrical and thermal properties are largely affected by morphological features (e.g., by the grain size and composition), we find in all cases that nanometer-sized polycrystalline G-hBN heterostructures are not good thermoelectric materials.
Keywords
- boron nitride, chemical vapor deposition, electrical properties, grain boundary, Polycrystalline graphene, thermal properties, thermoelectrics
ASJC Scopus subject areas
- Chemical Engineering(all)
- Bioengineering
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanical Engineering
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In: Nano letters, Vol. 17, No. 3, 08.03.2017, p. 1660-1664.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Electrical and Thermal Transport in Coplanar Polycrystalline Graphene-hBN Heterostructures
AU - Barrios-Vargas, José Eduardo
AU - Mortazavi, Bohayra
AU - Cummings, Aron W.
AU - Martinez-Gordillo, Rafael
AU - Pruneda, Miguel
AU - Colombo, Luciano
AU - Rabczuk, Timon
AU - Roche, Stephan
N1 - Funding information: J.E.B.-V. acknowledges support from CONACyT (Mexico, D.F.). This work was supported by European Union Seventh Framework Programme under grant agreement 604391 Graphene Flagship (R.M.G.). S.R. acknowledges the Spanish Ministry of Economy and Competitiveness for funding (MAT2012-33911), the Secretaria de Universidades e Investigacion del Departamento de Economia y Conocimiento de la Generalidad de Cataluna, and the Severo Ochoa Program (MINECO SEV-2013-0295). M.P. and L.C. acknowledge Spanish MINECO (FIS2015-64886-C5-3-P) and Generalitat de Catalunya (2014SGR301). B.M. and T.R. greatly acknowledge the financial support by European Research Council for COMBAT project (grant no. 615132).
PY - 2017/3/8
Y1 - 2017/3/8
N2 - We present a theoretical study of electronic and thermal transport in polycrystalline heterostructures combining graphene (G) and hexagonal boron nitride (hBN) grains of varying size and distribution. By increasing the hBN grain density from a few percent to 100%, the system evolves from a good conductor to an insulator, with the mobility dropping by orders of magnitude and the sheet resistance reaching the MΩ regime. The Seebeck coefficient is suppressed above 40% mixing, while the thermal conductivity of polycrystalline hBN is found to be on the order of 30-120 Wm-1 K-1. These results, agreeing with available experimental data, provide guidelines for tuning G-hBN properties in the context of two-dimensional materials engineering. In particular, while we proved that both electrical and thermal properties are largely affected by morphological features (e.g., by the grain size and composition), we find in all cases that nanometer-sized polycrystalline G-hBN heterostructures are not good thermoelectric materials.
AB - We present a theoretical study of electronic and thermal transport in polycrystalline heterostructures combining graphene (G) and hexagonal boron nitride (hBN) grains of varying size and distribution. By increasing the hBN grain density from a few percent to 100%, the system evolves from a good conductor to an insulator, with the mobility dropping by orders of magnitude and the sheet resistance reaching the MΩ regime. The Seebeck coefficient is suppressed above 40% mixing, while the thermal conductivity of polycrystalline hBN is found to be on the order of 30-120 Wm-1 K-1. These results, agreeing with available experimental data, provide guidelines for tuning G-hBN properties in the context of two-dimensional materials engineering. In particular, while we proved that both electrical and thermal properties are largely affected by morphological features (e.g., by the grain size and composition), we find in all cases that nanometer-sized polycrystalline G-hBN heterostructures are not good thermoelectric materials.
KW - boron nitride
KW - chemical vapor deposition
KW - electrical properties
KW - grain boundary
KW - Polycrystalline graphene
KW - thermal properties
KW - thermoelectrics
UR - http://www.scopus.com/inward/record.url?scp=85014290320&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.6b04936
DO - 10.1021/acs.nanolett.6b04936
M3 - Article
C2 - 28195494
AN - SCOPUS:85014290320
VL - 17
SP - 1660
EP - 1664
JO - Nano letters
JF - Nano letters
SN - 1530-6984
IS - 3
ER -