Numerical simulation of diffusion of electrons and holes in shocked silicon

The numerical method for simulation of diffusion of electrons and holes in the inertial field of a crystal under shock loading is developed. To analyze this diffusion, a complete system of electrodiffusion equations for charge carriers has been solved by means of the Poisson equation. Inertial forces were taken into account also by the drift-diffusion and convection-diffusion approximations. The equation system has been solved numerically by difference methods. Inertial currents in shocked Si are calculated for the shock wave with an amplitude of 1 GPa and different concentrations of doped impurity. It is shown that the shock wave traveling across the crystal creates an effective region of the electrical space charge that is moving along with the shock wave. The convection-diffusion model, describing inertial effects, is able of explaining large electric currents in shocked metals while the drift-diffusion model is not.