Popis: |
were reported.pNWs couple the nanowire 1-D structure to the unique character-istics of porous silicon, showing promise for the realization offlexible, biodegradable electronic and photonic biomedical deviceswith high sensitivity to the surrounding environment.In this study, we show the synthesis of pNWs regardless ofsiliconresistivity.Weemploymetal-assisted electrolessetchingtosynthesizeporoussiliconbarcodenanowires(nanobarcodes)withgeometry defined by lithography. The different porosity of eachnanobarcode segment determines its specific reflection andemission spectra, and yields multicolor nanobarcodes. Weenhance the segment-specific fluorescence of nanobarcodes bydifferential loading of two sizes of quantum-dots (Q-dots). Wepresent phase diagrams that describe the effects of the metalcatalyst, composition of the etching solution, Si doping type andresistivityontheresultingsiliconnanostructures:solidnanowires,porous nanowires, porous nanowires on porous silicon film,porous silicon films and polished surfaces. Furthermore, wedemonstrate that porous silicon nanowires dissolve in simulatedphysiological conditions and that the dissolution rate can becontrolled by surface functionalization. |