SERS Substrates by the Assembly of Silver Nanocubes: High-Throughput and Enhancement Reliability Considerations

Figure 4

(a) Schematic of the azimuth angle 𝜃 between the positive 𝑦-axis and the dimer axis, traced clockwise. (b) The dependence of the SERS signal on the orientation of the polarization of the laser with respect to the orientation of the axis of the dimer of silver nanocubes. The SERS signal anisotropy is calculated as (𝐼_𝑥(𝜃)−𝐼_𝑦(𝜃))/max(𝐼_𝑥,𝐼_𝑦) (see definitions in text). The theoretical relation (sin²𝜃−cos²𝜃)/max(sin²𝜃,cos²𝜃) is indicated by the blue dashed line. Data from dimers with SSEF >10⁵ (large circles) is closer to the theoretical trend than data from dimers with SSEF < 10⁵ (small circles). (c) Examples of two dimers of silver nanocubes, oriented at 𝜃=0 and 𝜃=𝜋/4, respectively. The nanocube size is 85 nm. Each dimer is located inside a pore.

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(b)

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