Conduction current characteristics and trap levels of nano-al2o3 composite polyimide films

Field dependent conduction current is one of the important characteristics of insulating material. The nano-Al₂O₃ composite polyimide films with Al₂O₃ content of 2.5%, 5%, 10% 12.5% and 15% in weight ratio were prepared respectively. The conduction current characteristics of the composite films and the variations of the conduction current with temperature were measured. The results show that, with increasing of the Al₂O₃, content and temperature, the conduction current increases and electric degradation threshold decreases. The trap energy level is from 0.55eV to 0.76eV corresponding to 2.5wt% to 15wt% content nanocomposite films respectively.