An investigation on the effect of substrate temperature and substrate type on physical properties of Sb2S3 thin films prepared by spray pyrolysis

Abstract

In this work, the effect of substrate temperature and substrate type on physical properties of the Sb2S3 thin film were investigated. First, Sb2S3 thin films have been deposited by spray pyrolysis method using an aqueous solution of antimony chloride and thiourea on the glass at a substrate temperature of 240 °C to 330 °C. Then, the deposition process of this layer has been done on fluorine- doped tin oxide (FTO) coated glass at a constant temperature of 300 °C. The structural, surface morphological, optical and electrical characterizations of the samples were carried out using X-ray diffraction, field effect scanning electron microscope, UV–vis spectroscopy, and four-probe apparatus, respectively. X-ray diffraction analysis showed that by increasing substrate temperature, the amorphous nature of the Sb2S3 thin film changed to the polycrystalline structure. Also, while the layer/glass sample has an individual Sb2S3 (orthorhombic) crystalline phase, the band gap values for Sb2S3 thin films prepared by increasing substrate temperature varied from 1.68 eV to 1.75 eV. Data analysis showed the Sb2S3 thin film on both substrates had a relatively high absorption coefficient (∼105 cm−1) in the visible range, and the direct bandgap had a smaller value in the layer grown on glass compared to that grown on FTO coated glass substrate. Electrical measurements exhibited the Sb2S3/FTO sample had a lower sheet resistance and resistivity than the Sb2S3/glass sample.