a low-cost stable sers substrate based on modified silicon nanowires

In this paper, we report fabrication of a simple, stable, low-cost, and easy-to-fabricate substrate for surface enhanced raman spectroscopy (sers) applications. silicon nanowires are one of the widely used nanostructures in different fields of nanotechnology. through creating and varying the gap between nanowires and reducing their filling ratio and tapering, silicon nanowires are converted to applicable sers substrates. furthermore, the effects of annealing and post-koh etching on these silver-coated silicon nanowire substrates are examined. it is shown that the applied processes remarkably enhance the captured raman signal. for samples etched with koh method, an optimized etching time at which the raman signal reaches its maximum value is obtained as well. finally, an ultra-high enhancement in the raman signal is obtained.