Fabrication of Plasmonically Active Ag Thin Films in the Region of Quasi-amorphous to Nanocrystalline and its Application towards SERS

The transition from quasi-amorphous to nanocrystalline state of Ag film is studied on plasmonically active ultra-thin silver films. The vital mechanisms for thin film formation known as coalescence and Ostwald ripening have been discussed. Surface plasmon resonance (SPR) is robust in the region of highly disordered to less disordered phase of Ag structure. The surface oxidation of Ag nanoparticles is studied by confocal Raman spectroscopy. The effect of SPR on Surface Enhanced Raman Scattering (SERS) enhancement of Rhodamine-6G (Rh6G) molecules studied by altering crystallinity, interparticles distance, size distribution and number density of Ag nanoparticles.