A rough 3D quasi-quantum plasmonic system with obviously enhanced SERS performance

Recently, the quantum and quasi -quantum plasmonic systems have attractive much attention in the design of surface -enhanced Raman scattering (SERS) substrate. The purpose of this work is to experimentally demonstrate an idea of introducing a rough spacer layer into the quasi -quantum plasmonic system for obtaining enhanced SERS performance. This idea was implemented in a simple 3D structure containing Au film, Raman active molecules, alumina spacer layer, and Au nanoparticles, where the rough spacer layer was prepared by dropping method and atomic layer deposition. The hybrid structure with a 4 nm alumina spacer demonstrated obviously higher amplification times of Raman signal than some previous works related to the plasmonic systems.