Formation and Study of Bismuth Sulphide Thin Films on Textiles of Different Compositions

The study aimed to form thin Bi2S3 films simultaneously on various textile materials using the environmentally friendly, low-cost successive ionic layer adsorption and reaction (SILAR) method at ambient temperature, and to evaluate the influence of the textile’s composition on the resulting composites’ surface phase composition, morphology, and optical properties. The deposited films were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and ultraviolet–visible (UV-Vis) diffuse reflectance spectroscopy. This paper discusses how the structure and composition of the textiles affect the phase and elemental composition, crystallinity, morphology and optical properties of the formed films. The properties of the films are then compared. Depending on the textiles used, the formed films can be amorphous or polycrystalline, and can be rich in sulphur or near stoichiometric. Accordingly, the normalised atomic percentages of Bi in the films range from 3.62% to 33.87%, and those of S range from 96.38% to 66.13%. The optical energy gap value of the composites also varies depending on the textile substrate, ranging from Eg = 1.58 eV to Eg = 1.8 eV. These properties directly impact the films’ applications. We have obtained a rather low value of the optical energy gap in a simpler way.