Optical characterization of CuIn5S8 crystals by ellipsometry measurements

IŞIK M., Gasanly N.

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, vol.91, pp.13-17, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 91
  • Publication Date: 2016
  • Doi Number: 10.1016/j.jpcs.2015.11.020
  • Journal Name: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.13-17
  • Keywords: Semiconductors, Optical materials, Optical properties, SINGLE-CRYSTALS, GROWTH, TEMPERATURE
  • Middle East Technical University Affiliated: Yes

Abstract

Optical properties of CuIn5S8 crystals grown by Bridgman method were investigated by ellipsometry measurements. Spectral dependence of optical parameters; real and imaginary parts of the pseudodielectric function, pseudorefractive index, pseudoextinction coefficient, reflectivity and absorption coefficients were obtained from the analysis of ellipsometry experiments performed in the 1.2-6.2 eV spectral region. Analysis of spectral dependence of the absorption coefficient revealed the existence of direct band gap transitions with energy 1.53 eV. Wemple-DiDomenico and Spitzer-Fan models were used to find the oscillator energy, dispersion energy, zero-frequency refractive index and high-frequency dielectric constant values. Structural properties of the CuIn5S8 crystals were investigated using X-ray diffraction and energy dispersive spectroscopy analysis. (C) 2015 Elsevier Ltd. All rights reserved.