Abstract

Making use of surface enhancement is a well-known technique to enhance characteristically weak Raman scattering signal. Surface enhance Raman scattering (SERS) is used in a wide range of research fields from life sciences to geology. The aim of this work is to develop a minimally sophisticated methodology to obtain cost-effective yet efficient enhancement surface structures useful for SERS. For that goal, laser-assisted photochemical etching was utilized to create nanoscale porous features on the surface of crystalline silicon substrates in a hydrofluoric acid solution. Process parameters such as etch duration, laser power, and beam shape were varied in order to obtain the optimum surface. The photochemically roughened substrates were then used as topographical templates and actual SERS action was enabled by a thermally evaporated 25 nm thick silver film on the surfaces. The fabricated SERS substrates were characterized by atomic force microscopy and the resulting Raman enhancement factors were measured using crystal violet molecules.

© 2018 The Author(s)