Bi-Dimensional Simulation of the Simplified Hydrodynamic and Energy-Transport Models Heter junction Semiconductors Devices Using Mixed Finite Elements

We study the application of the mixed finite elements method (MFE) for the bidimensional simulation of the simplified hydrodynamic and energy-transport models. The two main points are the use of entropic variables which gives a symmetric positive definite problem and a coupled computation of the equations for electrons which requires a generalization of the MFE method for vector valued problems. We give numerical results on JFET and HEMT devices.