Simulation on the electric field effect of Bi thin film

We report our simulation on the electric field effect of Bi thin film. Band diagram and carrier concentrations of the Bi channel at different surface potentials have been obtained by numerically solving Poisson's equation. In the calculation, the anisotropic characteristic of effective mass for carrier concentration and conductivity have been considered. The carrier densities were calculated from Fermi-Dirac integral. The conductivity effective mass ratio of electron and hole have been calculated to verify how the gate bias voltage affects the conductance of the Bi channel. The result shows that the Debye length in Bi is ~10 nm and nearly independent of the bias voltage. The dependency of conductance on gate bias is also discussed.