Morphological and thermal properties of β-SnS 2 sprayed thin films using Boubaker polynomials expansion

Abstract

In this work, β-SnS 2 thin films have been prepared on glass substrates by the spray pyrolysis technique using an alcohol solution which contains tin chloride (SnCl 4) and thiourea (SC(NH 2) 2) as precursors. The structural study shows that β-SnS 2 thin film prepared using optimal experimental conditions: substrate temperature T s = 280 °C and the concentration ratio of sulfur and tin elements in the spray solution x = [S]/[Sn] = 2.5, crystallizes in the hexagonal phase with a strong (0 0 1) X-ray diffraction line. In the same way, microprobe analyses (EPMA) as well as X-ray photoelectron spectroscopy (XPS) show the presence of undiserable phase of SnO 2. From the transmission and reflectance spectra, the band gap energy is 2.65 eV. On the other hand, the photothermal properties of such films have been studied, the thermal conductivity was K c = 0.85 W m −1 K −1 and the thermal diffusivity was D c = 14.5 × 10 −6 m 2 s −1. The analysis of β-SnS 2 thin films via the photodeflection spectroscopy including the effect of the inhomogeneity at the surface (roughness) and in the bulk (air inclusion, secondary phase of SnO 2) have been discussed for future investigations.