Origin of thickness dependent dc electrical breakdown in dielectrics

A model based on space charge dynamics under high dc electric field has been proposed to explain commonly observed thickness dependent breakdown of polymeric material. The formation and dynamics of space charge will result in local electric field enhancement that has a direct impact on dielectric breakdown. The simulation results show that the breakdown depends on the sample thickness with a power index of 0.143, indicating the space charge and its dynamics are responsible for thickness dependent breakdown. The model also predicts the effect of voltage ramping rate on the electrical breakdown strength.