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 (K-sp). 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 ratio decreases, indicating an increase in the amount of incorporated Hg into the ZnxHg1-xS system.

Automated summary

We successfully prepared ZnxHg1-xS thin films using chemical bath deposition. The amount of free Hg+2 ions in the mixed solution was controlled by using iodide anions to complex mercury. The films with different [I]/[Hg] ratios exhibited different compositions, as observed by scanning electron microscopy and UV-Vis spectroscopy.