Si nanowires as light emitting devices at room temperature and their manipulation by optical tweezers

Metal-assisted chemical etching using a ultrathin gold layer as a catalyst is a powerful technique to obtain high density and low-cost Si NWs with high and controllable aspect ratio and a radius compatible with quantum confinement effects. NWs obtained by this new technique have fully controllable doping properties; their main size is less than 10 nm allowing quantum confinement effects. We conducted a detailed study of the excitation and de-excitation properties as a function of the temperature and of the pump power, determining the excitation cross section and the presence of possible non-radiative phenomena1,2. Moreover, we designed a light emitting device based on Si NWs, demonstrating the EL emission at room temperature under low voltage pumping1. We show also the possibility to manipulate a single Si NW by optical tweezers. In fact, we investigated size-scaling in optical trapping of Si NWs showing how length regulates their trapping properties 3. The relevance and the perspectives of the reported results opening the route towards novel applications of Si NWs in photonic field.