Synthesis of MnS thin film: investigation of thickness-dependent physical properties

Herein, manganese sulfide (MnS) thin films are grown on glass substrates using the successive ionic layer adsorption and reaction (SILAR) method. SILAR is simple and inexpensive, does not require a high-quality substrate or vacuum environment, has no limitation on the size of the substrate material, has the ability to obtain materials at room temperature, shows easier doping process relative to other methods, and has the ability to control the growth rate and thickness of films. MnS with different thicknesses is coated on a glass surface, and various analyses are performed to examine the effect of the thickness on the film properties. Ultraviolet–visible analysis is used to examine the optical properties of the film, X-ray diffraction (XRD) spectrometry to examine its structural properties, and scanning electron microscopy and atomic force microscopy (AFM) to examine its morphological properties. XRD results indicate that the obtained MnS thin films have a cubic structure and achieve the highest peak intensity at 2θ = 32.87°. With increasing film thickness, the grain size increases from 9.20 to 13.36 nm and the energy band gap decreases from 3.32 to 3.02 eV. AFM results demonstrate that with increasing film thickness, the surface roughness value decreases from 84 to 53 nm. Moreover, increasing thickness improves the optical, structural, and morphological properties of the film.