孔洞聚丙烯驻极体膜中空间电荷与孔洞击穿电荷的俘获特性

Trap capture properties of space charge and void breakdown charge in a cellular polypropylene electret film

对孔洞聚丙烯(PP)驻极体膜系统的研究结果表明:孔洞PP膜中空间电荷的俘获特性随注入的空间电荷量或试样表面电位而变化,注入的电荷量较少时空间电荷主要被俘获在表面深陷阱和近表面次深陷阱中,较多的注入电荷量时空间电荷在进一步填充表层(表面和近表面)陷阱的同时,还将填充体内浅陷阱;这三类陷阱中心所对应的电荷脱阱温度分别约为160℃,138℃和92℃.而孔洞击穿电荷不仅被俘获在与试样表层空间电荷陷阱相似的孔洞表层陷阱中,还有相当的量穿过孔洞表层进入体内、成为浅阱俘获孔洞击穿电荷.

The following aspects have been indicated by systematic studies on the cellular polypropylene（PP） electret film.Trap capture properties of space charges changed with their injected amount or surface potential of the sample.The space charges were captured largely in the deep traps of the sample surface and the second-deep traps of the near-surface region at small amount of charge injection.They would fill these traps in the surface layer（surface and near-surface region） and the shallow traps in bulk at the same time in the case of greater amount of charge injection.The charge detrapping temperatures of the three kinds of trap centers are about 160℃,138℃ and 92℃,respectively.The charges formed due to void breakdown（called the void breakdown charges） were captured not only in the surface layers of voids which have similar traps as the surface layer of the sample,but also there were numerous void breakdown charges which penetrated the void surface layer,entered into the bulk,and were captured by the shallow bulk traps.