Computation of space charge-induced terminal current

Space charge induced phenomena in microscopic volumes can be studied through measurement of the space charge-induced terminal current using techniques which cancel the displacement current. The first order computation of such phenomena requires iterative solution for the electric field and related parameters with time-dependent voltage and field-dependent conductivity. Solutions have been published for 1-dimensional configurations (coaxial cylinders and concentric spheres) and for two-dimensional configurations. Various techniques are employed to solve for the current density, charge density, potential or field distribution, etc. as a function of time. The combination of a current density and a field implies dissipation which, in turn, implies a resistive terminal current. This resistive terminal current is presently the only measurable diagnostic for the field-induced phenomena which take place in the microscopic region surrounding a defect. Methods for computing this terminal current are, therefore, crucial to theoretical investigation of defect-induced space charge phenomena and are the subject of this contribution