Synthesis and Characterization of Silver Selenide Thin Films by Chemical Bath Deposition and Ionic Exchange

In this work, Ag2Se thin films were synthetized by a two-step technique at standard laboratory conditions. In the first step a silver hydrogen oxide carbonate thin film matrix was obtained by the chemical bath deposition technique. In the second step an ionic exchange between the matrix film and a new selenium ion solution was performed. The presence of silver and selenium atoms was detected by energy dispersive x-ray spectroscopy. From x-ray diffraction characterization, it was concluded there was an orthorhombic and polycrystalline structure for this material, Ag2Se. On the other hand, it was confirmed by transmission electron microscopy. The binding energies of silver and selenium were detected by x-ray photoelectron spectroscopy. From the ultraviolet-visible absorption spectra for the nanostructured Ag2Se thin film it was observed there was a blue shift in its bandgap, being 1.37eV, meanwhile the reported bulk bandgap value is 0.15eV.