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Enhanced Thermoelectric Performance of As-Grown Suspended Graphene Nanoribbons
- Source :
- ACS Nano. 13:9182-9189
- Publication Year :
- 2019
- Publisher :
- American Chemical Society (ACS), 2019.
-
Abstract
- Conventionally, graphene is a poor thermoelectric material with a low figure of merit (ZT) of 10^− 10^. Although nanostructuring was proposed to improve the thermoelectric performance of graphene, little experimental progress has been accomplished. Here, we carefully fabricated as-grown suspended graphene nanoribbons with quartermicron length and ∼40 nm width. The ratio of electrical to thermal conductivity was enhanced by 1−2 orders of magnitude, and the Seebeck coefficient was several times larger than bulk graphene, which yielded record-high ZT values up to ∼0.1. Moreover, we observed a record-high electronic contribution of ∼20% to the total thermal conductivity in the nanoribbon. Concurrent phonon Boltzmann transport simulations reveal that the reduction of lattice thermal conductivity is mainly attributed to quasi-ballistic phonon transport. The record-high ratio of electrical to thermal conductivity was enabled by the disparate electron and phonon mean free paths as well as the clean samples, and the enhanced Seebeck coefficient was attributed to the band gap opening. Our work not only demonstrates that electron and phonon transport can be fundamentally tuned and decoupled in graphene but also indicates that graphene with appropriate nanostructures can be very promising thermoelectric materials.
- Subjects :
- Materials science
General Physics and Astronomy
02 engineering and technology
010402 general chemistry
01 natural sciences
thermoelectricity
law.invention
law
Electrical resistivity and conductivity
Seebeck coefficient
Thermoelectric effect
Figure of merit
General Materials Science
electrical conductivity
Graphene
business.industry
General Engineering
suspended graphene nanoribbon
021001 nanoscience & nanotechnology
Thermoelectric materials
0104 chemical sciences
phonon transport
Optoelectronics
0210 nano-technology
business
Graphene nanoribbons
Subjects
Details
- ISSN :
- 1936086X and 19360851
- Volume :
- 13
- Database :
- OpenAIRE
- Journal :
- ACS Nano
- Accession number :
- edsair.doi.dedup.....9a9d0cb5feba5e03677c5b219b99d166