No abstract

The present paper reports on Tin Monosulphide (SnS) thin films elaborated by the Chemical Spray Pyrolysis (CSP) technique onto various substrates as simple glass, ITO-and Mo-coated glass in order to study the influence of substrates on the physical and chemical properties of SnS thin films. The structural analysis revealed that all films are crystallized in orthorhombic structure with (111) as the sole preferential direction without secondary phases. In addition, films prepared onto pure glass exhibits better crystallization compared to films deposited onto coated-glass substrates. Raman spectroscopy analysis confirms the results obtained from XRD with modes corresponding well to SnS single crystal orthorhombic ones (47, 65, 94, 160, 186, and 219 cm -1 ) without any additional parasite secondary phase like Sn 2 S 3 or SnS 2 . FESEM revealed that all films have cornflake like particles surface morphology and EDS analysis showed the presence of sulphur and tin with nearly stoichiometric ratio in films deposited onto pure glass. High surface roughness and large grains have been observed in film deposited onto glass. From optical spectroscopy it is inferred that band gap energy of SnS/glass and SnS/ITO were 1.64 eV and 1.82 eV, respectively.2

Zinc oxide (ZnO) thin films have been deposited using a SILAR (Successive Ionic Layer Adsorption and Reaction) technique, which is based on the alternate dipping of substrate in the solution and distilled water. The thin films were grown on copper, silicon and glass substrates. The precursors for ZnO films were diluted aqueous solution ZnSO4 complexed with NH3. The films were investigated by X-ray diffraction, scanning electron microscopy, XPS spectroscopy and spectrophotometer. XRD measurement showed that the films were crystallized in the wurtzite phase type with preferred orientation (002). X-ray photoelectron spectroscopy (XPS) was used to monitor changes in oxidation state of ZnO thin films. The XPS peaks of the O1s, Zn2p3/2 and Zn2p1/2 were used for studding the ZnO film. The results of influence of different parameters of SILAR method on phase structure, surface morphology, and optical properties are studied and discussed.

Indium sulfide (In 2 S 3 / thin films were prepared by chemical spray pyrolysis technique from solutions with different [S]/[In] ratios on glass substrates at a constant temperature of 250 ı C. Thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy and optical transmittance spectroscopy. All samples exhibit a polycrystalline structure with a preferential orientation along (0, 0, 12). A good stoichiometry was attained for all samples. The morphology of thin film surfaces, as seen by SEM, was dense and no cracks or pinholes were observed. Raman spectroscopy analysis shows active modes belonging to ˇ-ln 2 S 3 phase. The optical transmittance in the visible range is higher than 60% and the band gap energy slightly increases with the sulfur to indium ratio, attaining a value of 2.63 eV for [S]/[In] D 4.5.

The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis (CSP) is reported herein. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction (XRD) spectra revealed the polycrystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450 ºC), a crystalline phase corresponding to the Sn2S3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn2S3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250 °C and 350 ºC, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400 ºC films were denser and more compact. Energy dispersive X-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy (AFM) micrographs showed films well covered at 350 ºC resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased, and smaller values, 1.46 eV and 60Ω.cm, respectively, were attained at 450 ºC. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.