▎ 摘 要
A new current equation for graphene/semiconductor or graphene/metal junctions in graphene-based electronic devices is proposed based on the thermionic emission theory. Temperature-dependent current density predicted by the proposed model agrees well with those experimental data reported in the literature. It can also explain the electric field and temperature-dependent effective Schottky barrier height observed in experiments. This is because a high drift velocity in graphene and its dependence on temperature can lead to a change in the effective Schottky barrier height. Due to the nonlinearity between current and temperature, the Richardson's law will be broken down. The proposed model will benefit to better understand the current transport mechanism in graphene-like materials and graphene-based electronic devices.