Influence of laser and thermal treatment on the thermal conductivity of In-graphene composites

Graphene processed by thermal, laser, and thermal plus laser treatments was used to synthesize the indium-graphene composite foils. The symmetric nature of the G' band in the Raman spectrum was used to identify that the graphene was only few layers thick. Quantitative image analysis was used to determine the volume fraction of graphene. Electrical resistivity and temperature coefficient of resistance of the composite coupled with effective mean field approximation were analyzed to determine the volume fraction and resistivity of graphene. Thermal conductivity of the composite foils was measured using the three-omega method and multilayer analysis. The thermal conductivity of In-gr foils prepared by the three methods of processing graphene was found to be 1.8W/cm.K. The results indicate that the improvement in the thermal conductivity of the composites was same by the three methods of treatment of graphene. (C) 2011 American Institute of Physics. [doi:10.1063/1.3662181]