Electrochemical Evaluation of TCO Modifications Using Substituted Ferrocenes

Abstract

The modifications of transparent conductive oxides (TCOs) have been studied using an electrochemical evaluation technique (cyclic voltammetry (CV)). Substituted ferrocenes were chemically adsorbed onto the surface of indium tin oxide (ITO) and indium zinc oxide (IZO). The electroactive surface coverage, the redox potential, and the charge transfer rate of the adsorbed modifiers were evaluated using CV. The highest electroactive surface coverage was produced by ferrocene phosphonic acid while ferrocene acetic acid showed the fastest charge transfer rate. The charge transfers with the modified electrodes were evaluated in the presence of a solution electroactive probe. The charge transfer rate of the solution probe was enhanced with the modified electrodes compared to the charge transfer rate measured with unmodified electrodes. Even though the cause of the enhancement in the charge transfer rate is not clear, the results suggest that the modification of TCO may improve the charge collection efficiency of TCO, which is desirable for the application of TCO in devices such as organic photovoltaic cells.