Detailed characterization of good-quality SnS thin films obtained by chemical solution deposition at different reaction temperatures

A process for the chemical deposition of good-quality SnS thin films is presented. This process consists of a careful substrate sensitization; the placement of the substrate in a particular angle in the reaction solution; and the use of an aqueous reaction solution composed of stannous chloride, ethanol, triethanolamine, thioacetamide, and ammonium hydroxide. This process enables the deposition of good-quality SnS thin films that are homogenous and strongly adhered to the substrate, even at a temperature of 70 °C. The effect of reaction temperature (40, 45, 50, 55, 60, 65, and 70 °C) on the properties of the SnS thin films was studied by means of X-ray diffraction (including a Rietveld analysis), scanning electron microscopy, X-ray photoelectron spectroscopy, optical spectroscopy, and current photo-response. Rietveld analysis shows the presence of two tin sulfide orthorhombic phases (α-SnS and β-SnS) and a platelet-like microstructure with less than 20% of the total volume oriented in the (111) plane. Surface morphology confirms that grains have platey-like habits. It is found that with increasing reaction temperature the thin films increase in thickness, become more crystalline, and the conductivity photo-response improves, making the prepared SnS thin films suitable for optoelectronic applications.