title: Functionalization mediates heat transport in graphene nanoflakes.
abstract: 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 ∼28 °C for a chip operating at 1,300 W cm(-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.
authors.affiliation: Laboratoire EM2C, CNRS, CentraleSupélec, Université Paris-Saclay, Grande Voie des Vignes, 92295 Châtenay-Malabry, France.
authors.forename: Haoxue
authors.initials: H
authors.lastname: Han
authors.affiliation: SMIT Center, School of Automation and Mechanical Engineering and Institute of NanomicroEnergy, Shanghai University, 20 Chengzhong Road, Shanghai 201800, China.|Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Majid Kabiri
authors.initials: MK
authors.lastname: Samani
authors.affiliation: Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Ni
authors.affiliation: Quantum Technology Center, Physics Department, Lancaster University, Lancaster LA1 4YB, UK.|Science Department, Veterinary Medicine College, Al-Qasim Green University, Babylon, Iraq.
authors.forename: Zainelabideen Y
authors.identifier: http://orcid.org/0000-0002-8050-1504
authors.initials: ZY
authors.lastname: Mijbil
authors.affiliation: Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Edwards
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
authors.forename: Shiyun
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Department of Biomedical Engineering and Computational Science, Aalto University, FI-00076 Aalto, Finland.
authors.forename: Kimmo
authors.initials: K
authors.lastname: Sääskilahti
authors.affiliation: Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Murali
authors.initials: M
authors.lastname: Murugesan
authors.affiliation: Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.|SHT Smart High Tech AB, Ascherbergsgatan 46, SE-411 33 Gothenburg, Sweden.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Fu
authors.affiliation: SHT Smart High Tech AB, Ascherbergsgatan 46, SE-411 33 Gothenburg, Sweden.
authors.forename: Lilei
authors.initials: L
authors.lastname: Ye
authors.affiliation: Quantum Technology Center, Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Hatef
authors.initials: H
authors.lastname: Sadeghi
authors.affiliation: Quantum Technology Center, Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Bailey
authors.affiliation: Laboratoire EM2C, CNRS, CentraleSupélec, Université Paris-Saclay, Grande Voie des Vignes, 92295 Châtenay-Malabry, France.|Department of Polymers and Composite Materials, Semenov Institute of Chemical Physics, Russian Academy of Sciences, Kosygin Street 4, 119991 Moscow, Russia.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Kosevich
authors.affiliation: Quantum Technology Center, Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Lambert
authors.affiliation: SMIT Center, School of Automation and Mechanical Engineering and Institute of NanomicroEnergy, Shanghai University, 20 Chengzhong Road, Shanghai 201800, China.|Electronics Materials and Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, SE-412 96 Gothenburg, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratoire EM2C, CNRS, CentraleSupélec, Université Paris-Saclay, Grande Voie des Vignes, 92295 Châtenay-Malabry, France.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Volz