Silicon nanowires: A building block for future technologies

A fractal array of room-temperature (RT) luminescent Si nanowires (NWs) is realized by thin-film metal-assisted chemical etching, a cost-effective, fast, and maskless Si technology compatible approach. This process permits obtaining Si NWs with interesting structural and optical features for a wide range of applications, from photonics to sensing. For what concern photonics, the possibility to fabricate artificial fractals based on Si NWs that integrate other interesting elements is reported. In particular, an artificial fractal based on the Er:Y2O3 decoration of Si NWs where the Er emission can be tuned as a function of the decoration angle is shown. In the sensor field, the use of Si NW luminescence can represent an interesting and innovative sensing mechanism for the realization of a novel class of sensing platform. In this work, a light-emitting Si NWs-based label-free sensor for both selective isolation and ultrasensitive quantification of small extracellular vesicles (sEVs) is reported opening the route toward liquid biopsy applications.