  The authors report on synthesis and thermal properties of the
electrically-conductive thermal interface materials with the hybrid
graphene-metal particle fillers. The thermal conductivity of resulting
composites was increased by ~500% in a temperature range from 300 K to 400 K at
a small graphene loading fraction of 5-vol.-%. The unusually strong enhancement
of thermal properties was attributed to the high intrinsic thermal conductivity
of graphene, strong graphene coupling to matrix materials and the large range
of the length-scale - from nanometers to micrometers - of the graphene and
silver particle fillers. The obtained results are important for thermal
management of advanced electronics and optoelectronics.
