Thermal Conductivity Measurement of Graphene Exfoliated on Silicon Dioxide

Since graphene was first exfoliated from graphite, the monatomic layer of carbon atoms has attracted great interest for fundamental studies of unique two dimensional transport phenomena. Meanwhile, graphene is being explored for nanoelectronic applications because of the superior electron mobility and mechanical strength as well as compatibility with existing planar silicon-based microelectronics. The ultrahigh thermal conductivity suggested recently for suspended graphene is another attractive feature that may potentially address the increasingly severe heat dissipation problems in nanoelectronic devices. However, little is known about thermal transport properties of supported graphene that is used in most graphene device configurations. To better understand thermal transport in supported graphene, we have developed a device to measure the thermal conductivity of graphene exfoliated on a silicon dioxide beam. The obtained peak thermal conductivity is about 600 W/m-K near room temperature. This value is lower than the basal plane values for graphite and suspended graphene, but still considerably higher than common electronic materials. The measurement results at low temperatures further reveal intriguing low dimensional behaviors. Here, we present a detailed analytical and numerical heat transfer analysis of the thermal measurement method.