Buffer layer of antimony doped tin disulphide thin films for heterojunction solar cells

• Physical properties of Sb doped SnS2 films have been investigated.
• The crystallite size increases from 120 nm to 127 nm due to antimony doping.
• Band gap values varied from 2.75 to 2.05 eV as increase in doping concentration.

Antimony doped tin disulphide (SnS2:Sb) thin films have been prepared by the spray pyrolysis technique at the substrate temperature of 300 °C. The properties of the films were studied as a function of antimony dopant concentration (up to 10 at%). The XRD analysis revealed that the films were polycrystalline in nature and having hexagonal crystal structure with a preferred orientation along (002) direction. The optical energy band gap values were decreased from 2.50 eV to 2.05 eV with increase in Sb concentration and the PL spectra showed strong emission peak around at 470 nm. The film has the lowest resistivity of 1.088×102 Ω cm while higher carrier concentration was obtained at 8 at% of Sb.