| dc.identifier.citation | Ma, T., Liu, Z., Wen, J., Gao, Y., Ren, X., Chen, H., Jin, C., Ma, X. -L., Xu, N., Cheng, H. -M. & Ren, W. (2017). Tailoring the thermal and electrical transport properties of graphene films by grain size engineering. NATURE COMMUNICATIONS, 8 (1), https://doi.org/10.1038/ncomms14486. | |
| dc.description.abstract | Understanding the influence of grain boundaries (GBs) on the electrical and thermal transport properties of graphene films is essentially important for electronic, optoelectronic and thermoelectric applications. Here we report a segregation-adsorption chemical vapour deposition method to grow well-stitched high-quality monolayer graphene films with a tunable uniform grain size from ∼200 nm to ∼1 μm, by using a Pt substrate with medium carbon solubility, which enables the determination of the scaling laws of thermal and electrical conductivities as a function of grain size. We found that the thermal conductivity of graphene films dramatically decreases with decreasing grain size by a small thermal boundary conductance of ∼3.8 × 109 W m-2 K-1, while the electrical conductivity slowly decreases with an extraordinarily small GB transport gap of ∼0.01 eV and resistivity of ∼0.3 kΩ μm. Moreover, the changes in both the thermal and electrical conductivities with grain size change are greater than those of typical semiconducting thermoelectric materials. | |
