School of Electrical Engineering, Electromagnetic Engineering, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
ABB Corporate Research, SE 72178 Västerås, Sweden.
J Chem Phys. 2017 Feb 7;146(5):051101. doi: 10.1063/1.4975318.
Polymer nanocomposite dielectrics are promising materials for electrical insulation in high voltage applications. However, the physics behind their performance is not yet fully understood. We use density functional theory to investigate the electronic properties of the interfacial area in magnesium oxide-polyethylene nanocomposite. Our results demonstrate polyethylene conduction band matching with conduction bands of different surfaces of magnesium oxide. Such band bending results in long range potential wells of up to 2.6 eV deep. Furthermore, the fundamental influence of silicon treatment on magnesium oxide surface properties is assessed. We report a reduction of the surface-induced states at the silicon-treated interface. The simulations provide information used to propose a new model for charge trapping in nanocomposite dielectrics.
聚合物纳米复合材料电介质是高压应用中电绝缘的有前途的材料。然而，其性能背后的物理原理尚未完全理解。我们使用密度泛函理论研究了氧化镁-聚乙烯纳米复合材料的界面区域的电子性质。我们的结果表明，聚乙烯导带与氧化镁不同表面的导带相匹配。这种能带弯曲导致长达 2.6 eV 的深的长程势阱。此外，还评估了硅处理对氧化镁表面性质的基本影响。我们报告了在硅处理界面处表面诱导态的减少。这些模拟提供了用于在纳米复合材料电介质中提出新的电荷俘获模型的信息。
