Simulation of Electronic Properties, Enthalpy of Formation, and Dielectric Characteristics of Yb-Doped Single Crystal TlInS2

Using geometrically optimized supercells TlInS_2 and TlInS_2⟨Yb⟩ and density functional theory (DFT), the electronic properties of the samples have been calculated. The enthalpy of formation of TlInS_2 has been also calculated. It has been determined that TlInS_2 has a layered monoclinic system with sp. gr. C2/c— 1pt C_2h^6 . The frequency dispersion of the dielectric loss tangent ( tanδ ), real ( ε 1pt ' ), and imaginary ( ε 1pt” ) components of complex dielectric constant, and conductivity in alternating electric fields (ac-conductivity, σ_ac ) across layers in the frequency range f = 5 × 104–3.5 × 107 Hz have been studied. In the frequency range f = 5 × 104–2.4 × 107 Hz ac-conductivity of a single crystal TlInS_2⟨1 at % Yb⟩ has obeyed the law σ_ac ∼ f^0.8 , characteristic of hopping conductivity of charge carriers on states lying in the vicinity of the Fermi level. The density and energy spread of states near the Fermi level, the average time and distance of jumps, and the concentration of traps responsible for conductivity have been estimated for TlInS_2⟨1 at % Yb⟩ at alternating current.