Charge Storage Capabilities of Fractal Porous Silicon Obtained Using Simple Metal Assisted Porosification Method

Simpler methods for fabricating electrodes for charge storage applications are required because electrode materials have appreciable significance to enhance the electrochemical performance of charge/energy storage devices. Fractal porous silicon (pSi) substrate, prepared using a simple metal-assisted chemical etching (MACE) technique, has been studied here for possible application for charge storage. Electrochemical investigations have been carried out on the fabricated pSi electrodes, duly characterized using electron microscopy and Raman spectroscopy. The electrochemical performance of the prepared pSi electrode was studied using cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) in a three-electrode system. A comparative electrochemical measurement indicates more capacitive current flow in the pSi electrodes whereas c-Si shows an ohmic behavior. The equivalent circuit of the electrode-electrolyte system for pSi and c-Si was also drawn by the curve fitting of the Nyquist plot. The areal capacitance of the prepared pSi was also calculated at different scan rates and a moderate areal capacitance values were obtained which suggests that the pSi can be a possible candidate for the energy/charge storage electrodes.