基于类耿氏效应的低密度聚乙烯中空间电荷包行为的模拟仿真  

Numerical simulation of charge packet behavior in low-density polyethylene based on Gunn effect-like model

作　　者：夏俊峰[1] 张冶文[1] 郑飞虎[1] 雷清泉[2] 

机构地区：[1]同济大学波尔固体物理研究所,上海200092 [2]哈尔滨理工大学,哈尔滨150080

出　　处：《物理学报》2010年第1期508-514,共7页Acta Physica Sinica

基　　金：国家自然科学基金重点项目(批准号:50537040);国家自然科学基金(批准号:50807040);上海市科学技术委员会(批准号:07DZ22302)资助的课题~~

摘　　要：低密度聚乙烯材料中的空间电荷包现象通常会引起严重电场畸变而影响其击穿特性.本文借鉴半导体中的耿氏效应的负微分迁移率机理来描述电荷包的形成机理,并结合载流子的注入条件及体内陷阱对电荷迁移的影响等因素,对文献中报道的两类外加场强不同且迁移趋势各异的空间电荷包行为进行了模拟仿真,模拟的电荷包大小随电场变化规律,电荷包迁移速率随时间变化规律等与相应实验结果符合.模拟结果表明,产生耿氏效应的负微分迁移率是造成电荷包非弥散传输的主要原因,其与材料电极注入情况及体内陷阱态的共同作用导致了空间电荷包行为迁移的多样性.Packet-like space charge behavior usually induces the electric field distortion and strongly affects the electrical performance of low-density polyethylene. In this paper, we analyze the influence of charge injection, carriers migration and interaction between the free charge and trap in polyethylene on packet-like space charge behavior and introduce the mechanism of Gunn effect to describe the generating process of space charge packet. Based on this, we simulated two kinds of packet-like space charge behaviors with different variation trends and in different applied fields reported by different research groups. The simulated space charge packet shows very good fitting with the experiment data in both packet amplitude and migration velocity. The simulation results also indicate that the injection conditions and trap level depth play an important role in the diversity of packet- like space charge behavior.

关 键 词：空间电荷包 耿氏效应 模拟仿真 负微分迁移率 

分 类 号：O632.12[理学—高分子化学]