Repeated thermally deposited and annealed gold thin films as SERS-active substrate

Abstract

Size of gold nano-islands and gap between them is engineered using repeated gold film deposition and then annealing in the presence of argon gas. Increase in the density of nano-islands resulted in better SERS performance.

Defective Graphene/Plasmonic Nanoparticle Hybrids for Surface-Enhanced Raman Scattering Sensors

“…In the present case, at 514.5 nm laser excitation, the highest E-field enhancement of the order of ∼5 (see Figure c) is shown, which is a very close SPR absorption peak of Au NPs. Utilizing the widely available Lumerical software, we have done FDTD simulations of the DGR-Au and DGR-Au NP on the Si/SiO 2 substrate. − In accordance with the grain size of the annealed DGR-Au surface and as examined using FESEM and TEM images, the simulated electric field distribution between DGR-Au nanoparticles in the x – y plane is shown in the Supporting Information Figure S8b (illustrated in Figures and ). The color bar from blue to red shows the electric field’s increasing intensity.…”

“…Maxwell’s equation system is solved in the time-domain on a grid using a mathematical technique called finite domain time difference (FDTD), which computes the field distribution. − To analyze the electromagnetic (EM) fields in the gap between the suggested graphene and TM PNS hybrid structure or to study the plasmonic gap mode, FDTD calculations were carried out using the Lumerical FDTD solution software. The proposed design of the SERS-active substrate is based on gold (in the XY plane) on a thin layer of graphene, using Si/SiO 2 as a substrate, as illustrated in Figure .…”