Turkish Journal of Physics

Abstract: The structural and optical properties of CdTe thin films prepared at a low substrate temperature were investigated before and after the CdCl₂/annealing. The crystal structure of CdTe film was cubic with a strong (111) preferential orientation. Annealing at 400 °C without CdCl₂ treatment results in a decrease in the (111) peak intensity while the intensities of the (220), (311) and (331) peaks appeared, indicating that the texture is significantly changed. However, after the CdCl₂/annealing, the film exhibited a hexagonal phase as a dominant structure. The scanning electron microscopy patterns showed that the as-deposited and annealed samples had almost the same grain size. However, the grain size of the sample annealed after the CdCl₂ treatment increased significantly. The optical band gap values for the as grown and CdCl₂/annealed films were determined to be \sim 1.48 eV and \sim 1.49 eV, respectively.

Key Words: Thin films, vacuum deposition, electron diffraction, crystal structure