Figure 5: Schematic view of the corrosion mechanism where the corrosion starts with the presence of pinhole or crack in the pristine sample (a) at which the corrosion is initiated (b). The corrosion then expands in all directions until the substrate underneath the CdS is reached (c), after which the corrosion pit expands in lateral direction (d) until it merges with one or more neighboring corrosion pits (e).