聚丙烯孔洞铁电驻极体膜的电极化及其电荷动态特性

根据栅控恒压电晕充电组合反极性电晕补偿充电法的实验结果计算出铁电驻极体的极化强度.结果说明，伴随着薄膜内孔洞气体的Paschen击穿，该铁电体的极化强度随栅压增加而显著上升.利用上述充电方法和热刺激放电(TSD)谱的分析讨论了这类空间电荷型宏观电偶极子，及与其补偿的空间电荷热退极化的电荷动态特性；阐明了这两类俘获电荷的能阱分布，即构成宏观电偶极子的位于孔洞上下介质层内的等值异号空间电荷分别被俘获在深、浅两种能值陷阱内，而位于薄膜表面层的注入空间电荷则被俘获在中等能值陷阱中. 关键词： 反极性电晕补偿充电法 铁电驻极体 充电电流 热刺激放电

Electrical polarization and charge dynamics of cellular polypropylene ferroelectret films

In this work, the polarization of the ferroelectret was first estimated based on the experimental results of charging current by a corona charging with a grid in combination with the reverse-polarity corona charging compensation method. The experimental results indicated that the polarization drastically increases with the rise of grid voltage accompanying the breakdown of gas in the void. Also, by means of the charging method mentioned above and analyzing the thermally stimulated discharging spectra, the charge dynamics of macroscope dipoles with space charges and their compensation charges near the free surface of the film during thermal depolarization were discussed. A geometric distribution of trap levels trapping two kinds of charges was discovered, that is, the space charges formed in the macroscopic dipoles were trapped in shallow- and deep- energy level traps respectively, while the space charges located near the free surface of the film were trapped in medium energy level traps.