Electro-Raman measurement of thermal conductivity of suspended single and few-layer graphene*

We present measurements of the thermal conductivity of suspended graphene, using Raman spectroscopy on graphene subject to electrical heating. Joule heating is generated by passing a current through the suspended graphene, while the Cr/Au contact leads act as heatsinks. Raman spectrum is used as a thermometer for graphene, because of the temperature dependence of the amplitude and frequency for the G and 2D peaks. In order to extract the thermal conductivity of graphene, we measure the temperature distribution on the suspended graphene by Raman mapping of the 2-D and G peaks with graphene driven by various heating current. We can also determine the temperature dependence of the thermal conductivity. Our technique provides a simple method to measure thermoconductivity of graphene and can be generalized to other nanomaterials.