Liu C H, Hong M H, Cheung H W, Zhang F, Huang Z Q, Tan L S, Hor T S A
Department of Electrical and Computer Engineering, 4 Engineering Drive 3, Singapore 117576.
Opt Express. 2008 Jul 7;16(14):10701-9. doi: 10.1364/oe.16.010701.
Tuning of surface plasmon resonance by gold and silver bimetallic thin film and bimetallic dot array is investigated. Laser interference lithography is applied to fabricate the nanostructures. A bimetallic dot structure is obtained by a lift-off procedure after gold and silver thin film deposition by an electron beam evaporator. Surface plasmon behaviors of these films and nanostructures are studied using UV-Vis spectroscopy. It is observed that for gold thin film on quartz substrate, the optical spectral peak is blue shifted when a silver thin film is coated over it. Compared to the plasmon band in single metal gold dot array, the bimetallic nanodot array shows a similar blue shift in its spectral peak. These shifts are both attributed to the interaction between gold and silver atoms. Electromagnetic interaction between gold and silver nanostructures is discussed using a simplified spring model.
研究了金和银双金属薄膜及双金属点阵列对表面等离子体共振的调谐。采用激光干涉光刻技术制备纳米结构。通过电子束蒸发仪沉积金和银薄膜后，采用剥离工艺获得双金属点结构。利用紫外-可见光谱研究了这些薄膜和纳米结构的表面等离子体行为。观察到对于石英衬底上的金薄膜，当在其上覆盖银薄膜时，光谱峰发生蓝移。与单金属金点阵列中的等离子体带相比，双金属纳米点阵列在其光谱峰处也表现出类似的蓝移。这些位移都归因于金和银原子之间的相互作用。使用简化的弹簧模型讨论了金和银纳米结构之间的电磁相互作用。
