Effect of air annealing on structural, optical, morphological and electrical properties of thermally evaporated CdSe thin films

• The physical properties of CdSe thin films are undertaken.
• The XRD pattern reveals cubic phase of films with preferred orientation (111).
• The grain size is varied in the range 27.11–34.03 nm with air annealing.
• The extinction coefficient and refractive index are calculated.
• The electrical resistivity is found to be decreased with annealing temperature.

In this paper, a study on effect of air annealing on structural, optical, morphological and electrical properties of CdSe thin films is undertaken. The thin films of thickness 810 nm were deposited on glass and ITO coated glass substrates employing thermal evaporation technique. The glass substrates were used to find structural, optical and morphological properties while ITO coated glass substrates for electrical properties. The as-deposited films were subjected to thermal annealing in air atmosphere at different temperatures 100 °C, 200 °C and 300 °C. The X-ray diffraction pattern shows that the films have cubic phase with preferred orientation (111). The structural parameters like inter-planner spacing, lattice constant, grain size, dislocation density, strain and number of crystallites per unit area are calculated. The grain size is found in the range 27.11–34.03 nm and observed to be varied with air annealing. The dislocation density and strain vary with annealing in the range (0.86–1.36)×1011 cm−2 and 0.276–0.347 respectively. The extinction coefficient is found to be increased at lower annealing temperature and decreased at higher. The refractive index is also calculated and found in the range 2.75–2.80. The AFM studies show that roughness of thin films are increased with annealing. The electrical resistivity is found to be decreased with annealing temperature. The results are in good agreement with the standard data and available literature.

The X-ray diffraction pattern of as-deposited and annealed CdSe thin films.The X-ray diffraction pattern shows that the films have cubic phase with preferred orientation (111).The grain size is varied in the range 27.11–34.03 nm with air annealing.The extinction coefficient and refractive index are calculated.The electrical resistivity is found to be decreased with annealing temperature.Figure optionsDownload as PowerPoint slide