Synthesis and characterization of the chemically deposited SnS1-x Sex thin films: structural, linear and nonlinear optical properties

This article reported the synthesis of tin sulfide selenide (SnS1-x Se-x) thin films with different compositions (0 <= x <= 1) using a cost-effective chemical bath deposition technique. The structural properties of the chemically synthesized SnS1-x Se-x thin films were analyzed by means of the X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The XRD results demonstrate that all the chemically synthesized SnS1-x Se-x thin films are polycrystalline and displayed an orthorhombic phase corresponding to the different compositions. The compositional elements of the SnS1-x Se-x thin films were investigated via an energy dispersive X-ray analysis (EDAX). The optical study on the SnS1-x Se-x thin films displayed that the chemically deposited SnS1-x Se-x films exhibited a direct allowed optical transition and by increasing the Se content the magnitudes of the direct bandgap were decreased from 1.41-1.23 eV while the Urbach energy was increased. The effect of composition on the skin depth delta, absorption coefficient alpha, linear refractive index n and the static refractive index n(o) of the SnS1-x Se-x thin films was studied. Additionally, the results displayed that there is an improvement in the magnitudes of the nonlinear refractive index n(2), optical conductivity, third-order nonlinear optical susceptibility chi mml:mfenced close=)open=(3 mml:mfenced and the electrical conductivity of the SnS1-x Se-x thin films occurred by increasing the selenium content.