The Preparation And The Application For The SERS Substrate Of The Silicon Nano-holes/Wires

One-dimensional silicon nanometre materials have received intensive interests because of the unique effect of nanometer materials after its entering nanoscale and exhibiting excellent properties, such as thermal, optical and electrical properties, their unique properties of semiconductor that make them one of the potential materials for micro-nano electronic devices.This thesis mainly prepared silicon nanoholes and silicon nanowires by metal assisted chemical etching method, and metal or metal composite structure/silicon nanowire arrays by using silicon nanowires as substrate, and we also explored their SERS effect for R6G. The main research results are as follows:First, the preparation of silicon nanoholes and the influence of process parameters. The effects of the silver plating time, the concentration of silver nitrate and vacuum annealing on morphologies of the silver nanoparticles, and the relationship with the morphology of silver nanoparticles and the etched silicon nanoholes are discussed. There is no effect on etching direction by gravity and centrifugal force; the etching reaction can be accelerated by the increase of H2O2concentration and centrifugal force respectively. In the condition of small volume, etching rate will be increased with the increase of etching fluid volume, and after the volume of the etching solution reaching10ml, the pores turn into the nanostructure composed of nanowires and nanopores.Second, the preparation of silicon nanowires and the influence of process parameters. The optimal parameters of preparing silicon nanowires was obtained by changing the resistivity of silicon wafer, etching time and concentration of hydrofluoric acid:silver plating solution is the mixture solution of4.6Mol/L HF and0.01Mol/L AgNO3; the time of silver plating is1-2min, the etching solution is the mixed solution of10%-15%HF and1%H2O2, the etching temperature is70℃, the etching time is40min. The positive relationship between the resistivity of silicon, etching time, HF concentration and the length of the nanowires is also found respectively.Third, the SERS effect of the composite material between silicon nanowire array structure and the structure of the metal or metal composite material. Their (Ag/SiNWs, Au/SiNWs, Ag-Au/SiNWs) SERS effects for R6G were studied, the SERS effect of the SiNWs may be very weak and is not found; the SERS signal can be significantly enhanced by the Ag, Au or Ag-Au core-shell structure adhering to the SiNWs in their own best condition. The SERS signal of Ag-Au/SiNWs is the strongest, the SERS signal of Ag/SiNWs takes second place, the SERS signal of Au/SiNWs is the worst.