One-step construction of regular cascade nanostructure and its near-field properties

Uniform and simple construction of metal plasmon nanostructures has become popular for many applications. Thermal evaporative deposition technology has attracted widespread attention in recent years due to its excellent controllability and technical universality. In the current study, large area of uniform Ag cascade nanoparticle arrays (Ag-CNPAs) with multi-scale coupling effect were obtained by one-step method using the confined evaporation deposition technique. Finite-difference time-domain (FDTD) simulation findings demonstrated that Ag-CNPAs have apparent cascade enhancement feature of gradual energy coupling and convergence. Using prepared Ag-CNPAs as surface-enhanced Raman spectroscopy (SERS) active substrates, relative standard deviation (RSD) value of Raman intensity at 1160 cm-1 mode of crystal violet (CV) molecules (with concentration of 10-4 M) was 2.6 %, which indicated homogeneity and excellent near-field enhancement performance of AgCNPAs nanostructures. Furthermore, the current study established that SERS substrates were very promising devices. In addition, the current study developed a localized deposition technology that is simple to operate and cheap, which is valuable in large-scale uniform preparation of complex micro-nano structures.

Automated summary

The study successfully obtained large area uniform Ag cascade nanoparticle arrays with multi-scale coupling effect and cascade enhancement feature using confined evaporation deposition technique. The prepared Ag-CNPAs nanostructures exhibited excellent optical performance with homogeneity and near-field enhancement effect in SERS applications. The research results demonstrate promising applications of SERS substrates, and the developed localized deposition technology is simple and facilitates large-scale uniform preparation of micro-nano structures.