Year: 2010
Type: article
Abstract: The ability to propagate heat in a film should improve with increasing thickness. However, graphene has a higher thermal conductivity than graphite, despite having a smaller thickness. The crossover from two-dimensional to bulk graphite is now studied experimentally and explained theoretically. The results may pave the way to thermal management applications in nanoelectronics. Graphene1, in addition to its unique electronic2,3 and optical properties4, reveals unusually high thermal conductivity5,6. The fact that the thermal conductivity of large enough graphene sheets should be higher than that of basal planes of bulk graphite was predicted theoretically by Klemens7. However, the exact mechanisms behind the drastic alteration of a material’s intrinsic ability to conduct heat as its dimensionality changes from two to three dimensions remain elusive. The recent availability of high-quality few-layer graphene (FLG) materials allowed us to study dimensional crossover experimentally. Here we show that the room-temperature thermal conductivity changes from ∼2,800 to ∼1,300 W m−1 K−1 as the number of atomic planes in FLG increases from 2 to 4. We explained the observed evolution from two dimensions to bulk by the cross-plane coupling of the low-energy phonons and changes in the phonon Umklapp scattering. The obtained results shed light on heat conduction in low-dimensional materials and may open up FLG applications in thermal management of nanoelectronics.
Source: Nature Materials
DOI: 10.1038/nmat2753
Institutions: University of California, Riverside, Moldova State University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2141992264