Metal Nanoparticle–Nanowire Assisted SERS on Film

The electromagnetic field redistribution in metal nanostructure–film systems exhibits great capability of confining light on plain film, which has great significance in surface-enhanced Raman scattering (SERS) of a molecule on plain film or 2D material. In this work, the SERS spectra of a monolayer molecule on metal or dielectric film were investigated with the help of a metal nanoparticle–nanowire structure. The results indicated that SERS intensity from an adjacent nanoparticle was much greater than that from an individual nanowire, which was confirmed by the simulated electric field distribution through finite method. The polarization dependence of both experimental and simulated data pointed out the importance of electromagnetic field redistribution in this phenomenon. Furthermore, the shape independence of a nanoparticle found in this work greatly improved the application prospect of this nanoparticle–nanowire assisted SERS on film.