The effect of the electrolyte concentration on the charge transfer at the electrolyte/silicon-carbon interface: Electrochemical impedance spectrometry study

Abstract

Silicon-carbon films were synthesized by electrochemical deposition from methanol/ethanol and hexamethyldisilazane solution. SEM studies have shown that samples with manganese and those obtained from the methanol-based electrolyte are distinguished by the presence of three-dimensional agglomerates on the surface, while the morphology of films obtained from ethanol-based solution is more uniform. Raman studies confirm the formation of silicon-carbon bonds and the effect of manganese addition on the film structure. Electrochemical behavior was studied using the Mott-Schottky analysis. The plots of all samples contain linear sections with both positive and negative slopes, which indicates n-type and p-type semiconductor behavior The highest charge carrier density was found in the “pure” silicon-carbon films obtained from the methanol-based solution. The Bode plots showed a mix of resistive and capacitive behavior and they do not change much with the type of the sample and electrolyte concentration.