Incorporation of Bi, Cd and Zn on the optical properties of Ge20Se80 thin films

✍ Scribed by K.A. Aly; N. Afify; A.M. Aboushly

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 399 KB
• Volume: 405
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2010.01.060

✦ Synopsis

Different compositions of amorphous Ge 20 Se 80 and Ge 20 Se 75 M 5 (M= Cd, Bi, or Zn) semiconducting films were deposited onto cleaned glass substrates by thermal evaporation method. The interference transmission spectra T(l) at normal incidence for Ge 20 Se 75 M 5 thin films were obtained in the wavelength range 400-2500 nm. The direct analysis proposed by Swanepoel that is based on the use of the extremes of the interference fringes was used in order to derive the film thickness and the two parts of the complex refractive index (real part, n, and imaginary part, k,). The dispersion of n is discussed in terms of the Wemple-DiDomenico single-oscillator model. Furthermore, the optical band gap, E g , has been determined from the absorption coefficient values using Tauc's procedure. The obtained results of E g were discussed in terms of the width of localized state E e .