Characterization of carbon thin films electrodeposited on Aluminium, Copper and Silicon substrates

Carbon thin films were deposited on Aluminium(Al), Copper(Cu) and Silicon(Si) substrates by electrolysis of methanol. The effect of camphor (C₁₀H₁₆O) a natural source, incorporation with methanol is investigated. Camphor with varying amount was mixed in methanol solvent to prepare the electrolytes. Al, Cu and Si substrates were mounted on the negative electrode. Remarkable change in the variation of current density as a function of applied potential was observed with the camphor content. Thin films deposited on Al, Cu and Si substrates for different percentage of camphor are compared. It is found that for all the substrates the current density decreases initially with camphor from that of only methanol solution and increases thereafter. However, there is a limit for camphor to add in methanol solution for increasing current density. The optimum percentage of camphor to get maximum current density was observed to vary with substrate. For both Al and Cu substrates current density was highest for the 2% camphor in methanol solution but for Si substrates current density was highest for 6% camphor in methanol solution. Among the three substrates Si shows highest current densities for all level of voltages. Electron Dispersion Spectroscopy (EDS) analysis of three electrodeposited films were compared. Maximum carbon percentage was found for the electrodeposited films on Si substrates. The films were characterized by Fourier Transform of Infrared (FTIR) spectroscopy. Existence of hydrogenated amorphous carbon (a-C: H) bond were found for the films deposited on Al, Cu and Si substrates. The FTIR spectroscopy also indicates presence of both sp² and sp³ C-H stretch for the films deposited on Si substrate. But there is no clear indication of the presence of sp²/sp³ C-H stretch for the film deposited on Cu and Al.