Article ID Journal Published Year Pages File Type
1691862 Vacuum 2006 6 Pages PDF
Abstract

The optical constants (absorption coefficient (α), refractive index (n), extinction coefficient (k), real and imaginary part of dielectric constant) have been studied for a-Se96−xTe4Agx   (where x=0x=0, 4, 8, 12) thin films as a function of photon energy in the wavelength range (500–1000 nm). It has been found that the optical band gap increases while n and k decreases on incorporation of Ag in Se–Te system. The value of α and k increases, while the value of n decreases with incident photon energy. The results are interpreted in terms of the change in concentration of localized states due to the shift in fermi level. A correlation between the optical band gap and electronegativity of the alloys indicates that the optical band gap increases with the decrease of electronegativity.

Related Topics
Physical Sciences and Engineering Materials Science Surfaces, Coatings and Films
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