First principles study of Bi12GeO20: Electronic, optical and thermodynamic characterizations

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Işık M., Sürücü G. , Gencer A., Hasanlı N.

MATERIALS TODAY COMMUNICATIONS, cilt.27, ss.102299-102305, 2021 (SCI Expanded İndekslerine Giren Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 27
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.mtcomm.2021.102299
  • Sayfa Sayıları: ss.102299-102305


Bismuth germanium oxide (Bi12GeO20)  is  one of  the attractive members of  sillenite compounds having fasci-nating photorefractive characteristics. The electronic, optical and thermodynamic properties of Bi12GeO20 were investigated using density functional theory (DFT) calculations. The experimental and calculated X-ray diffraction patterns were obtained as well-consistent with each other. The lattice constant of the cubic crystalline structure of Bi12GeO20 compound was calculated as 10.304 Å. The electronic band structure and partial density of states plots were reported and contribution of constituent atoms (Bi, Ge, O) to the valence and conduction bands was presented. The band gap energy of the Bi12GeO20 was calculated as 3.20 eV. This wide direct band gap energy provides Bi12GeO20 significant potential in  ultraviolet applications. The spectra of  real and imaginary components of dielectric function, refractive index, extinction coefficient and absorption coefficient were drawn in the 010 eV energy range. Temperature-dependent heat capacity plot indicated the Dulong-Petit limit as 825 J/mol.K. The results of the present study would present worthwhile information to device application areas of Bi12GeO20 compound.