Optical Properties of Magnetic Semiconductors TlFeS2 and TlFeSe2

Badalova Z., Cahangirli Z., Abdullayev Y. A., Ragimov S., MEHDİYEV B., Hidiyev K. A., ...More

Physics of the Solid State, vol.67, no.6, pp.469-477, 2025 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 67 Issue: 6
  • Publication Date: 2025
  • Doi Number: 10.1134/s106378342560116x
  • Journal Name: Physics of the Solid State
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, INSPEC
  • Page Numbers: pp.469-477
  • Keywords: band structure, dielectric function, extinction coefficient, reflection coefficient, refractive index, spectral ellipsometry, Urbach energy
  • Open Archive Collection: Article
  • Azerbaijan State University of Economics (UNEC) Affiliated: Yes

Abstract

Abstract: The spectral dependences of the optical conductivity and reflection coefficients of TlFeS2 and TlFeSe2 crystals were studied experimentally using spectral ellipsometry and theoretically from first principles using density functional theory (DFT). Based on ellipsometric data in the energy range of 0.7–6.5 eV, the widths of the indirect band gap Eg, reflection coefficients R, Urbach energy EU, skin depth, and other parameters were determined. Analysis of the refractive index spectrum using the single-effective-oscillator model yielded estimates of the single oscillator energy Eso and the dispersion energy Ed. The experimental data were also used to determine the plasma frequency and the ratio of the charge carrier concentration to the effective mass. Furthermore, the nonlinear refractive indices and the first- and third-order nonlinear susceptibilities were calculated.