Chemical bath deposition of mercury (II) sulfide thin layers

Thin layers of mercury(II) sulfide have been prepared by a newly developed chemical bath deposition technique. The layers were grown on glass substrates previously coated with a very thin layer of lead sulfide(thickness <10 nm). The deposition was performed in alkaline media at 65 degrees C from thiosulfate complexes of mercury. X-Ray investigation indicates that the deposited material is a mercury(II) sulfide mixture of two phases, alpha-HgS and gamma-HgS, with alpha-HgS dominant. The optical bandgap, E-g, was evaluated from VIS absorption spectra and found to have a value of 3.1 eV.