Shape and deposition angle control of silver film-over-nanosphere SERS substrates

Thin metallic films on dielectric nanospheres are demonstrated to have a high potential for fabrication of cost-effective SERS substrates. In addition the morphological advantages that offer attaining density hot-spots, possessing shape adjustability by uncomplicated thermal treatment make them an attractive platform tuneable Furthermore, when combined with oblique angle metal deposition technique, adjustable gaps at and films, such as Ag can be achieved nanospheres. Applying small changes in provide means fine adjustment Raman enhancement factor (EF), resulting EF up 108 measured using crystal violet dye molecule analyte. This practice paves way substrates reasonable cost monolayer self-organized nanosphere pattern. An ultra-thin film coated 5o tilt is shown excellent substitute deposited 0o double thickness. There strong agreement between experimental results finite-elements-method based Maxwell simulations exhibiting expected field enhancements 109 5o.