Optical property evaluation of oxyfluoride glasses doped with different amounts of Y3+ ions

Abstract In present study, oxyfluoride glasses doped with different amounts of Y 2 O 3 (0.5, 1 and 1.5 wt.%) were prepared by the convenient melting process. Based on the density measurements and differential thermal analysis (DTA) results, the network-forming role of Y 3 + ions was proved. In addition, Fourier transform infrared spectroscopy (FT-IR) study of the samples approved this claim by showing structural changes happening with the increase of Y 2 O 3 content. Using the UV–Vis spectra, optical properties including Fermi energy level, direct and indirect optical band gaps and Urbach energy were determined. The mentioned optical properties were calculated using Fermi–Dirac distribution function, Tauc's plots and absorption coefficient diagrams, respectively. Increment of optical properties with the increase of Y 2 O 3 content (i.e. decrease of Fermi energy level from 3.59 to 3.17 eV, indirect band gap from 3 to 2.79 eV and direct band gap from 3.57 to 3.42 eV) confirms the better semiconducting behavior. Moreover, Urbach energy decreased from 0.27 to 0.23 eV arising from the network forming role of Y 3 + ions in the glass network.