Synthesis of manganese sulfide (MnS) thin films by chemical bath deposition and their characterization

Films of γ-MnS were deposited by chemical bath deposition (CBD) technique on glass slide substrates. The EDAX analysis showed that the film contains Mn and S elements without any other impurity. The EDAX weight percentage showed the film to be in perfect stoichiometry. The XRD showed that the synthesized MnS thin film possess hexagonal structure. The determined lattice parameters a = b = 3.9 Å and c = 6.4 Å were in match with the reported values. The crystallite size determined using XRD pattern employing Scherrer's formula and Hall-Williamson plot were 8.35 nm and 7.42 nm, respectively. The SAED shows ring pattern, clearly stating the thin film to be polycrystalline in nature. The SEM image of MnS thin film clearly reveals that the film surface is homogenous consisting of two sizes of spheres. Smaller spherical grain particles of size ∼1.6-2 μm covers the substrate and on top of covered small grain size particles are the large size spherical grain particles having size ∼5.0-7.0 μm. The 2D AFM image of MnS thin film shows coalescences between spherical grains. The optical absorbance analysis of the MnS thin film confirmed that the film possesses direct and indirect optical bandgap values of 3.67 eV and 2.67 eV, respectively. All the obtained results have been deliberated in this paper.