Percolation and dielectric breakdown

A simple percolation model is put forward to give a qualitative analysis for intrinsic breakdown in insulating polymers. The electron´s migration in polymers should be electron hopping-conduction between localized states. When the electrical field is high enough so that electron´s hopping probability between localized states is increased to a threshold, the localized electron wave function will overlap to form a percolation path which corresponds to the extended state. Finally, breakdown will be induced by the electron multiplication process or Auger effect in the extended state