Cuprous oxide induced the surface enhanced Raman scattering of silver thin films

In this work, silver thin films with various thicknesses deposited on cuprous oxide (Cu2O) buffer layer were obtained. XRD and AFM results show that the Cu2O buffer layer has the effect of improving the surface quality and crystallinity of the Cu2O-Ag composite films. The coupling between Cu2O and localized surface plasmons of the silver thin films was investigated by optical absorption and Raman scattering experiments. The absorption spectra showed that the intensity of Cu2O/Ag composite thin films was increased and shifted from the visible to the near-infrared region with an increase of the silver layer thickness. Compared with single-layer sample, the Raman scattering intensity of Cu2O/Ag composite was increased by 19.97 and 1.48 times, respectively. By the FDTD simulation of single layer and composite films, the electric field enhancement characteristics of the composite structure are confirmed. At the same time, the composite also exhibits good property as a SERS substrate for probing various molecules such as RhB, MB, and R6G.

Automated summary

The study found that the Cu2O buffer layer can improve the surface quality and crystallinity of the Cu2O-Ag composite films, while an increase in the thickness of the silver layer results in increased absorption intensity and a shift towards the near-infrared region in the spectrum. Raman scattering experiments showed a significant increase in the scattering intensity of the composite films, and FDTD simulations confirmed the electric field enhancement characteristics of the composite structure.