Comprehensive Atomistic Modulating of ThCu₂X₂ (X = N, P, As, Sb, Bi) Compounds for Opto-Electronic and Thermo-Electric Applications

ThCu₂X₂ structural, electrical, optical, and thermo-electric properties were analyzed using density functional theory, where X stands for N, P, As, Sb, and Bi substances. The energy bandgap is lowered by substituting Bi for the pnictogen components N. According to earlier calculations, all substances are semiconducting and have direct (G-G) and indirect (G-M) bandgaps between 2.49 eV and 0.90 eV. The X-s/p and Ba-f/d levels of the conduction and valence bands must strongly hybridize in order for electrical transport to occur. The dielectric function, ε₁(0), as well as the static reflectivity, R(0), exhibit an inverse relationship with the energy bandgap (Eg). At temperatures between 300 K and 800 K, the thermo-electric features were investigated with the BoltzTraP code. Since electron transport is dominated by hole carriers, all substances are p-type materials that are thermo-electric.