论文标题
单晶和多晶金等离子纳米棒的结构和光学特性
Structural and optical properties of monocrystalline and polycrystalline gold plasmonic nanorods
论文作者
论文摘要
等离子结构通常是通过薄金属膜的光刻图案制成的。薄膜的性质与所得结构的质量密切相关。在这里，我们比较了硝化硅上的两种薄金膜：一种传统的多晶薄膜，该薄膜由木ement子溅射沉积，单晶金晶层沉积，单晶金晶层首次在膜表面上直接在膜表面上进行化学合成。两种原始金属都使用聚焦离子束光刻来制造等离激元纳米棒。通过分析透射电子显微镜表征纳米棒的结构和光学特性。 The dimensions of the nanorods in both substrates reproduced well the designed size of $240 \times 80\ \mathrm{nm^2}$ with the deviations up to 20 nm in both length and width.从同一微板材料制造的单晶纳米棒中，形状的可重复性大大提高。有趣的是，单晶纳米棒具有倾斜的边界，而多晶纳米棒的边界是直立的。 Q在两个结构中模式的因素和峰值损失概率在实验不确定性之内。我们得出的结论是，当使用多晶金属而不是单晶金属时，等离子天线的光学响应不会恶化。
Plasmonic structures are often fabricated by lithographic patterning of a thin metallic film. Properties of the thin film are intimately related to the quality of the resulting structures. Here we compare two kinds of thin gold films on silicon nitride membrane: a conventional polycrystalline thin film deposited by magnetron sputtering, and monocrystalline gold microplates which were chemically synthesised directly on the membrane's surface for the first time. Both pristine metals were used to fabricate plasmonic nanorods using focused ion beam lithography. Structural and optical properties of the nanorods were characterized by analytical transmission electron microscopy. The dimensions of the nanorods in both substrates reproduced well the designed size of $240 \times 80\ \mathrm{nm^2}$ with the deviations up to 20 nm in both length and width. The shape reproducibility was considerably improved among monocrystalline nanorods fabricated from the same microplate. Interestingly, monocrystal nanorods featured inclined boundaries while the boundaries of the polycrystal nanorods were upright. Q factors and peak loss probabilities of the modes in both structures are within the experimental uncertainty identical. We conclude that the optical response of the plasmonic antennas is not deteriorated when the polycrystalline metal is used instead of the monocrystalline metal.
