On the chemical bath deposition of the ternary compound ZnxHg1-xS

We report on a strategy to obtain ZnxHg1-xS thin films by chemical bath deposition, to overcome the difficulties due to the enormous difference between HgS and ZnS solubility products (Ksp). Thin films containing the ternary compound were obtained using iodide anions to complex mercury, which allowed manipulating the amount of free Hg+2 ions in a mixed ethanol-water media, at room temperature. Three mercury containing films were deposited using different [I]/[Hg] ratios; along with a control ZnS film. The films obtained using the two lowest [I]/[Hg] ratios, contained mercury rich cinnabar crystallites over a ZnxHg1-xS layer, while the film with the highest ratio, contained zinc rich ZnxHg1-xS grains over a zinc rich layer, as it was observed by scanning electron microscopy measurements. UV–Vis spectroscopy results showed a ZnS-like absorption edge that shifts to lower energies as the [I]/[Hg] ratio decreases, indicating an increase in the amount of incorporated Hg into the ZnxHg1-xS system.