高电场下聚酯薄膜中陷阱捕获电子的特性研究

本文用表面电位测试技术研究了固体介质在强电场作用下陷阱捕获电荷的动力学特性.作者在考虑了碰撞电离退陷阱化后,获得的一级捕获动力学方程,定性地解释了电荷的捕获随施加电场的时间而变化的关系和捕获电荷稳态值随电场的增强而下降的现象。利用这个动态平衡模方程,经实验分析表明:这种捕获电荷稳态值随电场的增强而下降的现象是由于自由电子与陷阱化电子碰撞电离退陷阱化的结果,而不是陷阱化电子隧道效应或Poole-Frenkel效应的结果。当电场增强使碰撞电离退陷阱化达到一定程度时,介质便发生击穿。

ELECTRON CAPTURE CHARACTERISTIC OF TRAP IN PET FILM UNDER HIGH ELECTRICAL STRENGTH

The dyanmiac properties of electron capture of traps in solid dielectrics under high electrical strength are studied with the surface potential potential meansurement in this parer. By considering thr detrap- ping of electrons caused by collision ionization, a dynamic equation of first-order of trapping de- duced.So the variation of trapped electrons with time of applied voltage and the reduction of steady- state values of trapped electrons with increasing of electrical strength can be explained qualitatively. It is shown by test results that the decreasing of this steady-state value is caused by detrapping due to electron collision ionization between the free electron and the trapped one instead of tunnelefect or Poole-Frenkel effect of trapped electrons. Once the collision ionization reaches a certain degree,thr electrical breakdown of dielectrics occurs.