Derivation of the optical constants of thermally-evaporated uniform films of binary chalcogenide glasses using only their reflection spectra

• Published in: Thin solid films Vol. 317; no. 1; pp. 223 - 227
• Main Authors: González-Leal, J.M, Márquez, E, Bernal-Oliva, A.M, Ruiz-Pérez, J.J, Jiménez-Garay, R
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01.04.1998; Elsevier Science
• Subjects: Binary chalcogenic glasses; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical constants; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Spectra; Binary chalcogenic glasses; Spectra; Optical constants; Thin films; Thickness; Inorganic compounds; Arsenic sulfides; Reflection spectrum; Refractive index; Binary compounds; Experimental study; Germanium selenides; Optical absorption; Chalcogenide glasses
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(97)00519-1

Optical reflection spectra, at normal incidence, of binary chalcogenide glass thin films of chemical compositions As 25S 75 and Ge 33Se 67, deposited by thermal evaporation, were obtained in the 400 nm to 2200 nm spectral region. The optical constants of these particular amorphous materials were accurately determined using an optical characterization method proposed by Minkov, based on the maximum and minimum envelopes of the reflection spectrum, which allows to obtain both the real and the imaginary parts of the complex refractive index, and the film thickness. The dispersion of n is discussed in terms of the single-oscillator Wemple–DiDomenico model. The optical gap has been determined from the absorption coefficient values by Tauc's procedure.