Electrochemical impedance spectroscopy analysis of porous silicon prepared by photo-electrochemical etching: current density effect

摘要: Electrical impedance characteristics of porous silicon nanostructures (PSiNs) in frequency function were studied. PSiNs prepared through photo-electrochemical etching method at various current densities (15–40 mA/cm2) and constant time. The atomic force microscope images show that pore diameter roughness increase when density increases to 35 mA/cm2. surface subsequently decreases because continuous pillars, a second process occurs. Photoluminescence spectra blue red shift with increasing applied is attributed size. Variations electrical resistance capacitance values measured using electrochemical spectroscopy analysis. These results indicate 20 mA/cm2 have uniform structures large number pillars. Furthermore, this structure influences charge transfer double layer capacitance, indicating potential application sensors.