Ag dendrite formed on the Cu pyramids as SERS substrate

Ag dendrite formed on the Cu pyramids was fabricated as the SERS substrate by wet etching of Si, magnetron sputtering and galvanic displacement process. A flat sample with Ag dendrite on Cu film was prepared as a reference. The SEM results show that the Ag dendrite structure formed on the Cu pyramids exhibits much larger surface area and more nanoparticles and gaps than the flat one. Rhodamine 6G (R6G) was used to testify the Raman enhancement characteristics. It shows that the Raman peak intensity of the composite structure is 1.5 times larger than the flat one.