Effect of deposition cycle and annealing on the structural, optical, electrical, and photoluminescence properties of SnS films obtained from rapid S-SILAR technique

In this paper, we present an optimized procedure for depositing SnS thin films using the rapid S-SILAR technique. We also analyze the effects of deposition cycles and post-deposition annealing on various film properties. XRD analysis indicates the presence of orthorhombic and cubic phases in the films. Energy dispersive X-ray analysis confirms near-optimal stoichiometry. SEM images depict the growth of closely spaced spherical granules. High optical absorption is observed in the mid-visible to NIR region, with the absorption edge shifting towards the NIR region after annealing. The bandgap values range from 1.6 eV to 1.9 eV, which is ideal for photovoltaic applications. PL spectra show three clusters of peaks corresponding to red and green emissions. Hall measurements confirm that both the as-deposited and annealed SnS films exhibit p-type conductivity, with a hole concentration on the order of 10¹⁵ cm⁻³.