利用光刺激放电方法研究了线性低密度聚乙烯(LLDPE)中的陷阱能级分布,分别介绍了连续扫描与分段扫描这两种扫描方式并对它们进行了对比.指出在通常使用的连续扫描过程中,光刺激脱阱的不彻底给实验数据带来了一定的误差,着重讲述了分段扫描的理论基础以及实验过程.实验结果表明:单一波长辐照下的光刺激衰减电流的对数与时间成线性关系,它和分段扫描方法中的理论分析完全符合,同时也验证了在本实验中忽略载流子的重俘获过程是合理的;LLDPE中的俘获电荷位于4.14—6.22eV的陷阱能带内,但它们主要集中在陷阱能级为4.78—5.18eV的窄陷阱能带内.
The distribution of trap levels in the low density polyethylene(LDPE) was studied by means of photo-stimulated discharge(PSD).And two scanning modes,continuous scanning and step scanning,were discussed.It was pointed out that there may be some problems because of the incomplete detrapping of the trapping charges for the continuous scanning.The principle and the experimental process for the step scanning were presented.It is found that there is a linear relationship between the logarithm of PSD current produced under the irradiation of the monochromatic light and the time,which is in accordance with the theoretical analysis and indicates that the retrapping effect of the carriers can be neglected.The charges are trapped in the levels of 4.36—6.22 eV in LDPE,the main part of which were trapped in the energy levels of 4.78—5.18 eV.