Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
Nanotechnology. 2017 Jan 6;28(1):015301. doi: 10.1088/0957-4484/28/1/015301. Epub 2016 Nov 29.
By combining shadow nanosphere lithography with a glancing angle co-deposition technique, mixed-phase Ag-Cu triangular nanopatterns and films were fabricated. They were prepared at different compositions with respect to Ag from 100% to 0% by changing the relative deposition ratio of each metal. Characterizations by ellipsometry, energy dispersive x-ray spectroscopy, and x-ray diffraction revealed that the thin films and nanopatterns were composed of small, well-mixed Ag and Cu nano-grains with a diameter less than 20 nm, and their optical properties could be described by an effective medium theory. All compositions of the nanopattern had the same shape, but showed tunable localized surface plasmon resonance (LSPR) properties. In general, the LSPR of the nanopatterns redshifted with decreasing composition. Such a relation could be fitted by an empirical model based on the bulk theory of alloy plasmonics. By changing the colloidal template and the material deposited, this fabrication technique can be used to produce other alloy plasmonic nanostructures with predicted LSPR wavelengths.
通过将阴影纳米球光刻与掠角共沉积技术相结合，制备了混合相 Ag-Cu 三角形纳米图案和薄膜。通过改变每种金属的相对沉积比，从 100%Ag 到 0%Ag 制备了不同组成的 Ag-Cu 纳米图案和薄膜。通过椭圆光度法、能量色散 X 射线光谱法和 X 射线衍射对其进行的表征表明，薄膜和纳米图案由直径小于 20nm 的小而混合良好的 Ag 和 Cu 纳米颗粒组成，其光学性质可以用有效介质理论来描述。纳米图案的所有组成都具有相同的形状，但表现出可调谐的局域表面等离子体共振（LSPR）性质。一般来说，随着组成的减少，纳米图案的 LSPR 发生红移。这种关系可以通过基于合金等离子体学体理论的经验模型来拟合。通过改变胶体模板和沉积的材料，这种制造技术可以用于产生具有预测 LSPR 波长的其他合金等离子体纳米结构。
