External pressure effect on the electronic, optical and thermoelectric properties of the CdY(2)Ch(4) (Ch = S, Se) spinel compounds: Via modified Becke-Johnson (mBJ) exchange potential

Batouche M., Belfarh T., Mohammed D. E. S., Tabeti A., Seddik T., Ugur Ş., ...More

PHYSICA B-CONDENSED MATTER, vol.545, pp.40-47, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 545
  • Publication Date: 2018
  • Doi Number: 10.1016/j.physb.2018.06.006
  • Journal Name: PHYSICA B-CONDENSED MATTER
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.40-47
  • Keywords: FP-APW plus lo, Structural properties, Electronic properties, Optical properties, Pressure effect, THIOSPINELS, CDY2S4, EARTH, MN2, EPR
  • Gazi University Affiliated: Yes

Abstract

We report the results of the FP-APW + lo calculations of the structural, electronic, optical and thermo-electric properties of the CdY(2)Ch(4) (Ch = S, Se) compounds under hydrostatic pressure effect. The calculated ground state properties agree well with the available experimental data. The investigated materials are semiconductors, with direct band gaps (G-G) of approximately 2.18 eV, 1.53 eV for CdY2S4 and CdY2Se4, respectively, using GGA-TBmBJ approximations. Under external pressure up to 20 GPa, both compounds show a linear decrease of energy gaps against pressure. Moreover, our calculated optical spectra over photon energies ranging from 0 to 20 eV suggest that CdY(2)Ch(4) (Ch = S, Se) spinel compounds express a strong response in the energy range between the visible light and extreme UV regions, highlighting their possible application in the optoelectronic devices. Furthermore, the calculated thermoelectric properties indicate that both the CdY2S4 and CdY2Se4 compounds show interesting thermoelectric properties.