【摘要】 为了研究LDPE/Mg O纳米复合材料界面对不同三层结构空间电荷特性的影响,制备了纯LDPE薄膜以及4种不同界面的三层LDPE/MgO纳米复合薄膜。分别用电声脉冲法和光刺激放电法测试了这些薄膜的空间电荷特性和陷阱能级分布。实验结果表明,纳米Mg O颗粒的掺杂能够有效限制载流子在电介质内部的迁移,抑制空间电荷效果明显;在三明治结构复合材料的界面处存在大量的陷阱分布,这些陷阱可以捕获介质中的自由电荷,形成界面电荷层,电荷积累会削弱界面处的电场,并在界面处形成势垒,界面势垒也会抑制空间电荷的注入和迁移,降低消散速率。而且,界面相互作用对空间电荷特性的影响大于纳米颗粒掺杂。此外,界面结构的引入使薄膜中浅陷阱数量增多,深度为3. 55～5. 13 eV,空间电荷注入和消散速率降低,并且抑制了电荷的进一步注入和消散。更多还原

【Abstract】 In order to study the influence of the interface of LDPE/MgO nanocomposites on the space charge characteristics of different triple-layered structures,pure LDPE films and triple-layered MgO/LDPE nanocomposites with different structures were prepared. The space charge characteristics and trap level distribution of these films were tested by pulsed electro-acoustic( PEA) and photo-stimulated discharge( PSD) respectively. The PEA test results show that the doping of nano MgO particles restrict the transport of carriers in the dielectric and restrain the space charge. There are a large number of traps at the interface of sandwich structure composite materials. These traps can capture the free charge in the medium and form the interface charge layer. The charge accumulation will weaken the electric field at the interface and form a potential barrier at the interface. The interface potential barrier will also inhibit the injection and transfer of space charge and reduce the dissipation rate. Moreover,the sandwich structure has a more obvious blocking effect than the same dielectric interfaces. In addition,the introduction of interface structure leads to a large number of shallow traps in the thin film,with the depth of 3. 55 ～ 5. 13 eV,which reduces the rate of space charge injection and dissipation,and inhibits the further charge injection and dissipation.更多还原