Strong Substrate Dependence of Joule Heating in Graphene

The Joule heating effect on graphene electronic properties is investigated by using full-band Monte Carlo electron dynamics and three-dimensional heat transfer simulations self-consistently. A number of technologically important substrate materials are examined: SiO2, SiC, hexagonal BN, and diamond. The results illustrate that the choice of substrate has a major impact via the heat conduction and surface polar phonon scattering. Particularly, it is found that the poor thermal conductivity of SiO2 leads to significant Joule heating and saturation velocity degradation in graphene (characterized by the so-called 1/\surd n decay). Considering the overall characteristics, BN appears to compare favorably against other substrate choices for graphene in electronic applications.