We report the first temperature dependent phonon transport measurements in suspended Cu-CVD single layer graphene (SLG) from 15K to 380K using microfabricated suspended devices. The thermal conductance per unit cross section σ/A increases with temperature and exhibits a peak near T~280K (±10K) due to the Umklapp process. At low temperatures (T<140K), the temperature dependent thermal conductivity scales as ~T^{1.5}, suggesting that the main contribution to thermal conductance arises from flexural acoustic (ZA) phonons in suspended SLG. The σ/A reaches a high value of 1.7×105T1.5 W/m^2K, which is approaching the expected ballistic phonon thermal conductance for two-dimensional graphene sheets. Our results not only clarify the ambiguity in the thermal conductance, but also demonstrate the potential of Cu-CVD graphene for heat related applications.
@article{arxiv.1012.2937,
title = {Phonon Transport in Suspended Single Layer Graphene},
author = {Xiangfan Xu and Yu Wang and Kaiwen Zhang and Xiangming Zhao and Sukang Bae and Martin Heinrich and Cong Tinh Bui and Rongguo Xie and John T. L. Thong and Byung Hee Hong and Kian Ping Loh and Baowen Li and Barbaros Oezyilmaz},
journal= {arXiv preprint arXiv:1012.2937},
year = {2010}
}