Electro-performance of functionalized silicon nanowires by conductive polymer-coated with gold nanoparticles

In this paper, we present a novel technique to functionalize and enhance the efficiency of silicon nanowires (SiNWs) surface. SiNWs coated with a conductive polymer (polypyrrole (PPy)) prior to decoration with gold nanoparticles (AuNPs) was investigated. SiNWs and AuNPs were synthesized using metal assisted chemical etching (MACE) and Turkevich method respectively. The PPy was electrochemically polymerized on the surface of the SiNWs and visualized by scanning electron microscopy (SEM). Deposition of AuNPs on PPy/SiNWs surface was confirmed using Energy dispersive X-ray spectroscopy (EDS). Investigation of the AuNP@PPy/SiNWs composite using electrochemical impedance spectroscopy (EIS), compared to bare SiNWs and PPy/SiNWs structure, revealed significant enhancement of surface conductivity at low frequency where the charge transfer resistance decreases 80 times compared to that the bulk silicon in the end of the process and hence demonstrated effective electronic properties, primarily, the charge transfer at the semiconductor/electrolyte interface.