▎ 摘　　要

The presence of unknown thermal contact thermal resistance has limited prior two-probe thermal transport measurements of suspended graphene samples. Here, we report four-probe thermal transport measurements of suspended seven-layer graphene. By isolating the thermal contact resistance, we are able to attribute the observed reduced thermal conductivity primarily to polymeric residue on the sample instead of the contact thermal resistance, which resulted in ambiguity in the prior experimental studies of the effect of polymer reside. The extrinsic scattering rate due to the polymer residue is extracted from the measurement results based on a solution of the Peierls-Boltzmann phonon transport equation.