X-ray Diffraction Line Profile Analysis of Undoped and Se-Doped SnS Thin Films Using Scherrer's, Williamson-Hall and Size-Strain Plot Methods

An electrochemical route has been employed to prepare undoped and Se-doped SnS thin films. Six samples including undoped and Se-doped SnS thin films were deposited on the fluorine-doped tin oxide glass substrate. An aqueous solution containing 2mM SnCl2 and 16mM Na2S2O3 was used in the electrolyte. Different Se-doped SnS samples were prepared by adding the various amounts of 4mM SeO2 solution into the electrolyte. The applied potential (E), time of deposition process (t), pH, and bath temperature (T) were kept at -1V, 30min, 2.1, and 60 degrees C, respectively. After the completion of the deposition process, x-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to characterize the deposited thin films. XRD patterns clearly showed that the synthesized undoped and Se-doped SnS thin films were crystallized in the orthorhombic structure. Using Scherrer's method, the crystallite size of deposited thin films is calculated. In addition, the crystallite size and lattice strain have been estimated using the modified form of the Williamson-Hall (W-H) method containing a uniform deformation model, a uniform deformation stress model, a uniform deformation energy density model, and by the size-strain plot method (SSP). The shape of SnS crystals was spherical in TEM images. The results showed that there was a good agreement in the particle size obtained from the W-H method and the SSP method with TEM images.