The authors investigate the effects of nanofillers with varying band-gap energies on the space charge properties, breakdown field strength, and bulk resistivity of epoxy (EP)-based composites. Additionally, the molecular orbital distribution of both the epoxy resin and nanofillers were examined through density functional theory. Experimental results indicate that the space charge accumulation within silicon dioxide/EP and germanium oxide/EP is reduced, leading to a more uniformly distributed electric field intensity within the specimen when compared to epoxy. As a result, both materials exhibit improved AC breakdown field strength and volume resistivity. Conversely, the amount of charge accumulated within tin dioxide/EP is higher, resulting in lower breakdown field strength than epoxy. The lowest unoccupied molecular orbital and the highest occupied molecular orbital energy level differences between epoxy and nanofillers introduce electron traps and hole traps at the interface, forming interfacial traps that affect the space charge distribution within the specimen, as well as the trap energy levels within the material. From the experimental results, shallow traps promote space charge accumulation and reduce the breakdown field strength, while deep traps have the opposite effect.

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不同能级纳米填料对环氧基纳米复合材料电性能的影响

作者研究了不同带隙能量的纳米填料对环氧树脂 (EP) 基复合材料的空间电荷特性、击穿场强和体电阻率的影响。此外，还通过密度泛函理论检查了环氧树脂和纳米填料的分子轨道分布。实验结果表明，与环氧树脂相比，二氧化硅/EP和氧化锗/EP内的空间电荷积累减少，导致样品内电场强度分布更均匀。因此，两种材料都表现出改进的交流击穿场强和体积电阻率。相反，二氧化锡/EP 内积累的电荷量较高，导致击穿场强低于环氧树脂。环氧树脂和纳米填料之间的最低未占据分子轨道和最高占据分子轨道能级差异在界面处引入电子陷阱和空穴陷阱，形成界面陷阱，影响样品内的空间电荷分布以及样品内的陷阱能级。材料。从实验结果来看，浅陷阱促进空间电荷积累并降低击穿场强，而深陷阱则具有相反的效果。