Chemical deposition of cubic CdSe and HgSe thin films and their characterization

A modified chemical bath deposition method has been developed to prepare CdSe and HgSe semiconductor thin films in cubic modification, based on the chemical reaction of complexed cadmium acetate, mercuric nitrate with sodium selenosulphate in an aqueous ammoniacal medium at 5 degreesC. The films were characterized by using x-ray diffraction, optical absorption, electrical measurements and energy dispersive x-ray analysis techniques. The films were uniform, well adherent, dark red and polycrystalline in cubic form without trace of any hexagonality. The CdSe film shows two bandgaps at 2.15 and 1.86 eV, while HgSe shows two bandgaps at 0.8 and 0.45 eV. A thermoelectric study indicated the presence of an n-type conduction mechanism.