Surface-Enhanced Raman Scattering from Dye Molecules in Silicon Nanowire Structures Decorated by Gold Nanoparticles

Silicon nanowires (SiNWs) prepared by metal-assisted chemical etching of crystalline silicon wafers followed by deposition of plasmonic gold (Au) nanoparticles (NPs) were explored as templates for surface-enhanced Raman scattering (SERS) from probe molecules of Methylene blue and Rhodamine B. The filling factor by pores (porosity) of SiNW arrays was found to control the SERS efficiency, and the maximal enhancement was observed for the samples with porosity of 55%, which corresponded to dense arrays of SiNWs. The obtained results are discussed in terms of the electromagnetic enhancement of SERS related to the localized surface plasmon resonances in Au-NPs on SiNW's surfaces accompanied with light scattering in the SiNW arrays. The observed SERS effect combined with the high stability of Au-NPs, scalability, and relatively simple preparation method are promising for the application of SiNW:Au-NP hybrid nanostructures as templates in molecular sensorics.

Automated summary

This study explored the use of silicon nanowires (SiNWs) combined with gold nanoparticles (Au NPs) for surface-enhanced Raman scattering (SERS) of probe molecules. The research found that the filling factor of SiNW arrays controlled the SERS efficiency, with the highest enhancement observed for samples with a porosity of 55%. The results demonstrate the electromagnetic enhancement of SERS through localized surface plasmon resonances in Au-NPs on SiNW surfaces, accompanied by light scattering in the SiNW arrays.