Development of Sb2S3 as a double absorber layer with Sb2Se3 by Simple and Low Cost Chemical Bath Deposition Technique for Solar Cell Applications

Abstract

Antimony sulfide (Sb₂S₃) has been explored for its potential in optoelectronic applications. It was synthesized using a low-cost and facale chemical bath deposition (CBD) method. The resulting material showed an orange color, consistent with previous reports. This study focused on examining how varying concentrations of sodium thiosulphate (Na₂S₂O₃) affect the optical and morphological characteristics of Sb₂S₃. Additionally, the impact of annealing on these properties was also analyzed. Comprehensive characterization was carried out to assess structural, optical, and surface features. X-ray diffraction (XRD) results indicated that the as-deposited Sb₂S₃ films were amorphous. However, annealing at 200 °C enhanced the crystallinity of the material. Optically, the film deposited with a 2.0 M concentration showed 99% absorption in the blue line (450–495 nm) of the visible spectrum, while the 2.5 M sample exhibited similar absorption in the UV range. An increase in Na₂S₂O₃ concentration corresponds to a gradual rise in the energy bandgap. Atomic force microscopy (AFM) revealed that root mean square (RMS) roughness consistently decreased with increasing annealing temperature. However, changes in sodium thiosulfate concentration did not produce a clear trend in surface morphology. The surface roughness varied across different concentrations. Scanning electron microscopy (SEM) images showed the formation of large, mushroom-shaped grains around 8 µm in size, which reduced with annealing. The strong light absorption in both visible and ultraviolet regions suggests that Sb₂S₃ is a promising material for solar cell absorber layers and photodetector applications.