Functionalization mediates heat transport in graphene nanoflakes

Haoxue Han (1) , Yong Zhang (2, 3) , Nan Wang (3) , Majid Kabiri Samani (3) , Yuxiang Ni (4) , Zainelabideen y Mijbil (5, 6) , Michael Edwards (3) , Shiyun Xiong (7) , Kimmo Sääskilahti (8) , Murali Murugesan (3) , Yifeng Fu (3, 9) , Lilei Ye (9) , Hatef Sadeghi (5) , Steven Bailey (5) , Yuriy Kosevich (10, 1) , Colin J Lambert (5) , Johan Liu (2, 3) , Sebastian Volz (1)

1 EM2C - Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion
2 Shanghai University
3 Chalmers University of Technology [Göteborg]
4 Minnesota State University [Mankato]
5 Lancaster University
6 Green University of Al Qasim
7 Max Planck Institute for Polymer Research
8 Aalto University
9 SHT Smart High Tech
10 N. N. Semenov Institute of Chemical Physics

The high thermal conductivity of graphene and few-layer graphene undergoes severe degradations through contact with the substrate. Here we show experimentally that the thermal management of a micro heater is substantially improved by introducing alternative heat-escaping channels into a graphene-based film bonded to functionalized graphene oxide through amino-silane molecules. Using a resistance temperature probe for in situ monitoring we demonstrate that the hotspot temperature was lowered by B28°C for a chip operating at 1,300 W cm À 2. Thermal resistance probed by pulsed photothermal reflectance measurements demonstrated an improved thermal coupling due to functionalization on the graphene-graphene oxide interface. Three functionalization molecules manifest distinct interfacial thermal transport behaviour, corroborating our atomistic calculations in unveiling the role of molecular chain length and functional groups. Molecular dynamics simulations reveal that the functionalization constrains the cross-plane phonon scattering, which in turn enhances in-plane heat conduction of the bonded graphene film by recovering the long flexural phonon lifetime.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Thermique [physics.class-ph]; Micro et nanotechnologies/Microélectronique

Haoxue Han, Yong Zhang, Nan Wang, Majid Kabiri Samani, Yuxiang Ni, et al.. Functionalization mediates heat transport in graphene nanoflakes. Nature Communications, 2016, ⟨10.1038/ncomms11281⟩. ⟨hal-01336749⟩