β-In2S3 thin films doped by tin (Sn4+) and deposited by Chemical Spray Pyrolysis technique for photovoltaic applications

β-In₂S₃ thin films doped by tin at different percentages were deposited by Chemical Spray Pyrolysis (CSP) method at 300 °C substrate temperature onto glass substrate. X-ray diffraction (XRD) was used to study structure, Raman spectroscopy analysis for phase, quality and structure, Scanning Electron Microscopy (SEM) for the surface morphology, Energy Dispersive X-Ray Spectroscopy (EDS) for the composition, Atomic Force Microscopy (AFM) for surface topography and transmittance to determine the gap energy. The XRD analysis showed that the crystallographic structure of β-In₂S₃ is present on the deposited films with a preferential orientation along (0 0 12) and no secondary phase is observed. SEM images presented films well covered without crack and pinholes but different morphologies and AFM micrographs showed very compact films when the percentage of doping increased. Main mode at 327cm-1 is showed by Raman spectroscopy and from optical analysis, the transmission varied from 60% to 70% with band gaps estimated from 2.64 to 2.82 eV.