Evaluating the Practical Use of Digital Video to Study the Effect of Sheet Resistance of Transparent Indium-Tin Oxide Electrodes Using the Galvanostatic Deposition of Poly(o-toluidine)

Abstract

The galvanostatic deposition of poly(o-toluidine) (POT), a polyaniline derivative, on a long, narrow transparent indium-tin oxide (ITO) electrode was monitorized by digital video. This mixed electrochemical-optic technique allowed us to obtain sequential digital images of the deposition process synchronized with the electrochemical response. From each pixel of a digital image, red, green, and blue (RGB) color components were obtained and the color evolution against elapsed time during the electrodeposition and along the ITO surface was analyzed. Thus, we obtained spatiotemporal information about the effect of sheet resistance on the electrochemical reactions, the relative film coating, which can be an approximation of relative film thickness, the kinetics together with the spatial distribution of electrochemical reactions and the homogeneity of deposited film on ITO. Digital video monitorization provided very useful information about the quality of deposited POT, which could be extrapolated to control the coloration of any electrode surface used for electrochromic devices, smart windows, or dye-synthetized solar cells.