Corrosion of an amorphous indium tin oxide film on polyethylene terephthalate at low concentrations of acrylic acid

The corrosion behavior of ITO film deposited at low temperature on a polymer substrate by DC magnetron sputtering is studied in 0.05 M acrylic acid to investigate possible corrosion in contact with acrylic adhesives, which are employed in the fabrication of flexible optoelectronic devices. The shift in steady state open circuit potential (OCP) to negative values in electrochemical measurements suggests the increase in dissolution of ITO film with increasing immersion time. The potentiodynamic polarization results show an increase in Ecorr and a decrease in Icorr to lower values with time. This suggests that the electro-activity of ITO film decreases with increasing immersion time. Scanning electron microscopy shows corrosion of the ITO film. X-ray photoelectron spectroscopy analysis indicates a gradual removal of indium from the ITO layer. Electrochemical impedance spectroscopy analysis reveals two time constants and an increase in the charge transfer resistance of the Nyquist plot which suggests a decrease in the conductivity of ITO film with increasing immersion time. Both the electrochemical and surface characterization studies suggest a degradation of the conductivity of ITO film with increasing immersion time in 0.05 M acrylic acid.