Assessing the thermal conductivity of non-uniform thin-films: Nanocrystalline Cu composites incorporating carbon nanotubes

Abstract

We demonstrate a procedure for measuring the thermal conductivity of non-ideal thin-films with significant non-uniformity. By spatially mapping the thermal transport with time-domain thermoreflectance measurements, followed by statistical analysis, we determined the thermal conductivity of Cu composite films containing dispersed carbon nanotubes (CNTs). The thermal conductivity of the composite decreased from 188 to 60 W/m K as 1.8 wt. % of multi-walled CNTs was incorporated into nanocrystalline Cu. We compared the decreasing trend with that calculated from a scattering model to find out that the CNTs scatter the heat carriers in Cu. (C) 2011 American Institute of Physics. [doi:10.1063/1.3606559]