• Khan, Muhammad Salman
• Mohamed, Abdelhay Salah
• Gul, Banat
• Ahmad, Bashir
• Benabdellah, Ghlamallah
• Ahmad, Hijaz

Abstract

<jats:title>Abstract</jats:title><jats:p>The tunable optical characteristics and superior thermal stability of Indium and Thallium-based quaternary chalcogenides are significant. We studied the intricate relationship between the optoelectronic, and thermoelectric features of notable BaXCu<jats:sub>3</jats:sub>Se<jats:sub>4</jats:sub> (X = In, Tl) quaternary chalcogenides. Both the maximum of the valence band and conduction band coincide at the Γ-point, confirming these materials as direct band gap materials. By substituting Indium for thallium, the calculated band gap decreases from 0.71 eV to 0.53 eV. These anions have a considerable impact and contribute to a decrease in the energy gap via valence electrons. Partially filled d orbitals of copper play an important role in electronic states at the Fermi level. The components of the complex dielectric function, as well as other important optical parameters, are examined and analyzed for the potential usage in optoelectronic devices. The <jats:italic>ε</jats:italic><jats:sub>1</jats:sub>(<jats:italic>ω</jats:italic>) becomes negative at 6.32 eV, suggesting that the medium is reflecting all of the incident light. Thallium affects the absorption spectrum because it changes the density of states and electronic transitions. The absorption spectra indicated that the material absorbs in the visible and near-ultraviolet parts of the spectrum, which is fascinating and might have applications in optoelectronics. The investigated materials are appropriate to be used for thermoelectric devices confirmed by their significant and notable thermoelectric properties. Because the Seebeck coefficient is negative, most charge carriers, typically electrons, flow from the higher temperature area to the lower temperature region. At both low and high temperatures, thallium is accountable for BaTlCu<jats:sub>3</jats:sub>Se<jats:sub>4</jats:sub>’s higher thermal conductivity than BaInCu<jats:sub>3</jats:sub>Se<jats:sub>4</jats:sub> material.</jats:p>

Topics

• density
• impedance spectroscopy
• copper
• thermal conductivity
• Indium
• Thallium