Space-charge effects on current transport in media having cylindrical and spherical symmetries

摘要

Space-charge effects on transport in solids under a given applied potential are examined for cylindrical and spherical symmetries. It has been proven for these symmetries that a predominant space charge of the same sign as that of the mobile species produces a retardation of the current, whereas a dominant space charge of opposite sign to that of the mobile species enhances the current. Analytical expressions are developed which can be used to evaluate quantitatively the effects of the retardation or the enhancement for these geometries with arbitrary space-charge distributions.