Wang Hui, Tam Felicia, Grady Nathaniel K, Halas Naomi J
Department of Chemistry, Rice University, Houston, Texas 77005, USA.
J Phys Chem B. 2005 Oct 6;109(39):18218-22. doi: 10.1021/jp053863t.
The optical properties of metals arise both from optical excitation of interband transitions and their collective electronic, or plasmon, response. Here, we examine the optical properties of Cu, whose strong interband transitions dominate its optical response in the visible region of the spectrum, in a nanoshell geometry. This nanostructure permits the geometrical tuning of the nanoparticle plasmon energy relative to the onset of interband transitions in the metal. Spectral overlap of the interband transitions of Cu with the nanoshell plasmon resonance results in a striking double-peaked plasmon resonance, a unique phenomenon previously unobserved in other noble or coinage metal nanostructures.
金属的光学性质既源于带间跃迁的光学激发，也源于其集体电子响应或等离子体响应。在这里，我们研究了铜在纳米壳结构中的光学性质，在光谱的可见光区域，铜的强带间跃迁主导了其光学响应。这种纳米结构允许相对于金属中带间跃迁的起始点对纳米颗粒等离子体能量进行几何调谐。铜的带间跃迁与纳米壳等离子体共振的光谱重叠导致了显著的双峰等离子体共振，这是一种以前在其他贵金属或铸造金属纳米结构中未观察到的独特现象。
