Sb2S3 thin films: From first principles to in situ crystalline thin film growth by ultrasonic spray pyrolysis

In this paper, we report deposition of in situ crystallized photoconductive Sb2S3 thin films by direct ultrasonic spray pyrolysis using a non-aqueous precursor solution containing antimony chloride and thioacetamide, free from any complexing agent. Further, the First principles calculations of both vibrational and electronic band structures were done in the framework of Density Functional Theory. Experimentally, a systematic study on the thin film growth by varying substrate temperature (170–290 °C) and relative concentration of Sb/S (0.1–0.4) were evaluated. X-ray diffraction and Raman spectral analysis showed the formation of polycrystalline Sb2S3 films at 200 °C. These thin films were subjected to post deposition treatments of vacuum annealing and rapid thermal processing (RTP) to evaluate changes in their optoelectronic properties. Both as prepared and post thermal treated samples were with uniform surface coverage and compact morphologies. Also, the films were photoconductive with a direct band gap of 1.6 eV. The experimental results were in correlation with our theoretical calculations on the complete Raman spectra. This work offers a direct one step ultrasonic spray pyrolysis process to obtain polycrystalline photoconductive Sb2S3 thin films for various optoelectronic applications.