Transfer current in p-type graphene/MoS2 heterostructures

Transfer characteristics of p-doped graphene/monolayer-MoS2 heterostructure at 300 K are measured experimentally and analyzed based on a model calculation. In the model, we first discretize the Poisson equation into multiple zones. In each zone the charge density is assumed constant and the Poisson equation can be transformed into a linear equation to determine the chemical potential self-consistently. To calculate the electrical conductivity, we solve the Boltzmann transport equation in the relaxation-time approximation using the inelastic acoustic phonon scattering by solving the Dirac equation. The relationship between the Dirac voltage (the voltage at which the Fermi level is located at the Dirac point) and the Fermi energy (i.e. the initial chemical potential at 0 K) is derived. These calculations are performed without and with optical pumping and the results obtained agree well with the experimental data.