Thermal Annealing Effect on Surface-Enhanced Raman Scattering of Gold Films Deposited on Liquid Substrates

We prepare metal films with various thicknesses on liquid substrates by thermal evaporation and investigate the annealing effect on these films. Gold films deposited on a silicone oil surface consist of a large number of branched aggregates, which contains plenty of gold nanoparticles. This characteristic morphology is mainly attributed to the isotropic and free-sustained liquid substrate. Thermal annealing results in the reintegration of nanoparticles; thus, the surface morphology and microstructure of gold films change significantly. The dependence of annealing conditions on the surface-enhanced Raman scattering performance of gold films is studied, in which gold films show favorable Raman activity when annealed at certain annealing temperature and the experimental results are verified by simulation analysis. The study on the optimal annealing temperature of surface-enhanced Raman scattering substrate will pave the way for the potential application of films deposited on liquid surfaces in microfluidics and enhanced Raman detection.

Automated summary

We prepared metal films of different thicknesses on liquid substrates using thermal evaporation and studied the effect of annealing on these films. Gold films deposited on a silicone oil surface consisted of numerous branched aggregates containing abundant gold nanoparticles. Thermal annealing caused the reintegration of nanoparticles, resulting in significant changes in the surface morphology and microstructure of the gold films. The dependence of the annealing conditions on the surface-enhanced Raman scattering performance of gold films was investigated, and the experimental results were verified by simulation analysis. The study on the optimal annealing temperature of surface-enhanced Raman scattering substrate will facilitate the potential application of films deposited on liquid surfaces in microfluidics and enhanced Raman detection.