Influence of annealing times on the structural and optical dispersion parameters properties of thermally cadmium telluride films

Abstract EN

Thin CdTe films had been prepared by thermal evaporation technique on glass substrate under vacuum of about 10-5mbar.

The thicknesses of the films were 900±5 nm.

The films were annealed at different duration (60,90,and 180 ) minute.

The X-ray pattern showed that the prepared and annealed films were polycrystalline structure cubic phase with preferred orientation at (111) plane.

Absorbance spectra of the films indicates that the films had high absorption at the visible region.

The optical studies revealed that the transition was direct with band gap value decreased from 1.47eV to 1.36eV with increasing the duration of annealing.

Also , the optical constant such as refractive index , extinction coefficient and real and imaginary parts of dielectric constant were determined .The refractive index dispersion curves obeyed to the single oscillator's model.

The dispersion energy and single-oscillator energy varied with the duration of annealing.

The moments of optical spectra had been studied.

The infinite refractive index increased from 2.60 to 3.84 with increasing the duration of annealing.