Influence of post-deposition annealing temperature on the growth of chemically deposited Sb₂S₃ thin films

Sb₂S₃ is a potential material for solar cells because of the suitable optoelectronic properties as well as earth-abundant constituent elements. Post-deposition annealing treatment is a crucial step in the fabrication of high-quality crystalline Sb₂S₃ thin films. Herein, we analyzed the impact of annealing temperature on grain growth and morphology of Sb₂S₃ films by annealing them in an Ar atmosphere for 30 min. The as-grown Sb₂S₃ films were amorphous. On annealing the films at 250–350^∘C, crystallization of orthorhombic Sb₂S₃ occurred and its crystal size increased from 43 to 100nm. The surface morphology and grain growth were improved at an annealing temperature of 300^∘C when compared with those at temperatures 250^∘C and 350^∘C. The annealed Sb₂S₃ films exhibited direct energy gap values of 1.6–1.7 eV. The films exhibited p-type electrical conductivity. The electrical resistivity of the films decreases and hole mobility increases with increasing annealing temperature from 250 to 350^∘C. This study is vital for the optimization of the annealing temperature for growth of good-quality Sb₂S₃ films, which are necessary for solar cell applications.