Study on the effect of annealing temperature on the optical characteristics and microstructure of Sb2Se3 thin films

To achieve high conversion efficiency in Sb₂Se₃ thin films, the effects of different annealing temperatures on the optical properties and microstructure were investigated. The experiment shows that annealing improves Sb₂Se₃ films' refractive index, absorptivity, and reduces the optical band gap. The first-principle theoretical analysis reveals that defects in the films such as Sb_Se2, Sb_Se3, V_Se2, and V_Se3 significantly affect their optical band gap. Based on the XRD (X-ray diffraction) patterns, the half-height widths, average grain sizes, microstrains and dislocation densities of the diffraction peaks have been calculated. The results show that the optimal annealing temperature is 325 °C. Finally, EDS (Energy Dispersive Spectrometer) and Raman spectroscopy were used to explain the reasons for the changes in the optical properties and internal structure of the film with the annealing temperature from the perspectives of the changes in the film components and the bonding properties between the atoms.