Computational evaluation of novel barium zinc chalcogenides Ba2ZnCh3 (Ch = S, Se, Te) for advanced optoelectronic applications.

ABSTRACT

Due to their outstanding optoelectronic characteristics, ternary chalcogenides are considered an attractive choice for absorbers of visible light. Here, a novel family of ternary chalcogenides, Ba2ZnCh3 (Ch = S, Se, Te), is examined in the context of density functional theory calculations. The atomic locations in these materials are determined before the bulk modulus, cohesive energy, and lattice constant predictions. Our examined materials are semiconductors by nature, as indicated by the electronic band profiles with both the WC-GGA potential and TB-mBJ potential revealing an energy gap between the valence and conduction bands. Using full geometrical optimization and the force minimization technique based on Broyden's scheme, the interior atomic positions and the relaxed structures were obtained. The formation energies are likely more consistent with a convex hull near the configuration of interest. The cohesive energies confirmed that Ba2ZnS3 has the most cohesive nature as compared to the other two materials. Likewise, the calculated components of the dielectric function of the individual materials were anisotropic having dissimilar values along different dimensions. The computed sharp peaks of the absorption coefficient for Ba2ZnS3, Ba2ZnSe3, and Ba2ZnTe3 confirm their improved absorption behavior in the UV range. Moreover, the thermoelectric characteristics were computed, and the findings are detailed, indicating that all of these materials are efficient for thermoelectric device applications.