One pot synthesis of Sb2S3 nanocrystalline films through a PVP-assisted hydrothermal process

Abstract

In this paper, nanocrystalline antimony sulfide (Sb2S3) thin films were prepared on a tin-doped indium oxide (ITO) substrate via a facile polyvinylpyrrolidone (PVP)-assisted hydrothermal method. The crystal structure, morphology and optical properties of the Sb2S3 films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV–vis spectroscopy. Well-crystallized Sb2S3 films possessed a honeycomb-like morphology with a whole thickness of approximately 360 nm on the ITO substrate and had a band gap of 2.0 eV. The reaction parameters that influenced the formation of Sb2S3 films, such as reaction time, temperature and quantity of PVP were investigated. PVP was found to play an important role in the formation of the honeycomb-like Sb2S3 films. In the absence of PVP, only large aggregates formed on the ITO substrate. A possible growth mechanism of the Sb2S3 films has been proposed. Furthermore, the as-synthesized Sb2S3 film exhibited a photocurrent density of −0.025 mA cm−2 at 0 V (vs. RHE) in a neutral solution, close to that of the heated Sb2S3 film. A stability test demonstrated that the as-synthesized Sb2S3 film was stable in both neutral and acidic solutions. This investigation might provide a feasible method for preparing high-quality Sb2S3 films to be used in solar energy conversion.