Optical characterization of a-Se85 − x Te15Zn x thin films

• DOI: 10.1007/s12043-011-0222-0
• Publication Date: 2012-01-11T07:30:49Z
• Authors: S SHUKLA; S KUMAR
• Keywords: 0103 physical sciences; 01 natural sciences

Thin films of Se85 − xTe15Znx (x = 0, 2, 4, 6 and 10) glassy alloys have been deposited onto a chemically cleaned glass substrate by thermal evaporation technique under vacuum. The analysis of transmission spectra, measured at normal incidence, in the spectral range of 400–2500 nm helped us in the optical characterization of thin films under study. From the analysis of transmission spectra, the optical parameters such as refractive index (n), extinction coefficient (k), absorption coefficient (α), real and imaginary dielectric constants (e′ and e″) have been calculated. It is observed that the parameters n, k, e′, e″ and α decrease with increase in wavelength (λ) and increase with Zn content. Optical band gap (Eg) has also been calculated and found to decrease with Zn content in Se85 − xTe15Znx glassy system which could be correlated with increase in the density of defect states.