Photocorrosion of CuInSe2 Thin Film by Electrochemical Polarization in Acidic and Alkaline Medium

In this research the effect of varying surface morphology on photocorrosion behavior of CuInSe2 (CIS) was studied in acidic and alkaline electrolytes. Polycrystalline CIS thin films were deposited on to ITO glass by pulse electrochemical deposition method. Duty cycles of 90%, 75%, 50%, and 33 % for fifteen minutes (total on-time) were chosen to produce different surface morphologies during electrochemical deposition from aqueous solution. The photocorrosion rates were evaluated from the electrochemical polarization data. Polarization curves were acquired in selected corrosive electrolytes which contained 0.5 M KCl + H2SO4 as acidic media and 0.5 M KCl + NaOH as alkaline media. The photocorrosion rates for different morphologies were estimated by current density (icorr) extracted from Tafel plot in all the pH range. Finally activity and passivity behaviors of the thin films were determined by interpreting the polarization curve peaks (Ecorr) values and the rates of photocorrosions. The results proved photocorrosion behavior of deposited CIS thin film is affected by the surface morphology, and pH of the medium