The effect of shape, material and shell thickness on electric field distribution of both Ag@CuO and Ag@ZnO core–shell dimer is investigated. First, three core–shell structures, including plane@circle, triangle@circle and quadrilateral@circle are designed. The field enhancement advantages of the quadrilateral@circle structures are summarized by analyzing the electric field distribution diagrams. Then the influence of materials on the field enhancement effect of core–shell dimer is discussed. The results show that Ag@CuO structure has better stability, while Ag@ZnO structure have larger electric field enhancement. Finally, the shell thickness is changed from 0.1 nm to 1.5 nm. We found that the X-component electric field of both the Ag@ZnO and Ag@CuO core–shell dimer structure is decreased with the increase in the shell thickness. Also, the X-component electric field of Ag@ZnO core–shell dimer is about five times than that of the Ag@CuO. The increase of electric field indicated that Ag@ZnO core–shell dimer has strong local surface plasma resonance characteristics.

中文翻译：

---

Ag@CuO 和 Ag@ZnO 核壳二聚体的电场分布

研究了形状、材料和壳层厚度对 Ag@CuO 和 Ag@ZnO 核壳二聚体电场分布的影响。首先，设计了平面@圆形、三角形@圆形和四边形@圆形三种核壳结构。通过分析电场分布图，总结了四边形@圆形结构的场增强优势。然后讨论了材料对核壳二聚体场增强效应的影响。结果表明，Ag@CuO结构具有较好的稳定性，而Ag@ZnO结构具有较大的电场增强。最后，壳层厚度从 0.1 nm 变为 1.5 nm。我们发现，Ag@ZnO 和 Ag@CuO 核壳二聚体结构的 X 分量电场随着壳层厚度的增加而减小。还，Ag@ZnO 核壳二聚体的 X 分量电场约为 Ag@CuO 的 5 倍。电场的增加表明Ag@ZnO核壳二聚体具有很强的局部表面等离子体共振特性。