Electronic thermal conductivity measurements in intrinsic graphene

The electronic thermal conductivity of graphene and two-dimensional Dirac materials is of fundamental interest and can play an important role in the performance of nanoscale devices. We report the electronic thermal conductivity K sub(e) in suspended graphene in the nearly intrinsic regime over a temperature range of 20-300 K. We present a method to extract K sub(e) using two-point dc electron transport at low bias voltages, where the electron and lattice temperatures are decoupled. We find K sub(e) ranging from 0.5 to 11 W/m K over the studied temperature range. The data are consistent with a model in which heat is carried by quasiparticles with the same mean free path and velocity as graphene's charge carriers.