Indium—Tin Oxide Organic Interfaces

Abstract

We show here the detailed surface characterization of indium-tin oxide (ITO) thin films, and the effect of variations in surface composition on the electron transfer rates of a chemisorbed probe molecule, ferrocene dicarboxylic acid (Fc(COOH)2. Pretreatment schemes vary both the extent of hydroxylation of the ITO surface, and the relative concentration of oxide defects, which help to control electron transfer events at the ITO interface. In addition we show the first example of spectroelectrochemical characterization of charge injection processes at ITO interfaces with ultra-thin films of new discotic mesophase (phthalocyanine) molecular assemblies, using broad-band visible wavelength spectroelectrochemistry. Prism coupling schemes with ITO attenuated total reflectance (ATR) elements, and CCD detection, allow for simultaneous characterization of the 450-900 nm region during oxidative doping of these assemblies.