Influence of microstructure on the electrochemical performance of tin-doped indium oxide film electrodes.

The effect of the microstructure of tin-doped indium oxide (ITO) films on their electrochemical performance was studied using three redox probes, tris(2,2'-bipyridyl ruthenium(II) chloride (Ru(bpy)3(2+/3+)), ferrocyanide (Fe(CN)6(4-/3-)), and ferrocenemethanol (FcCH2H(0/+)). ITO films were deposited using dc magnetron sputtering under a variety of conditions that resulted in films having different degrees of crystallinity, crystallographic texture, sheet resistance, surface roughness, and percent tin. It was found that the electron transfer for all three redox probes used in this study was more efficient at polycrystalline films than at amorphous ITO films.