Optical, mechanical, and transport properties of selenium-based argyrodites

The silver based halide argyrodites Ag₆PSe₅X (X = Cl, Br I) have been studied using the density functional theory (DFT). The materials under analysis predicted to have lattice constants of 11.25 Å, 11.25 Å, and 11.28 Å for Ag₆PSe₅Cl, Ag₆PSe₅Br, and Ag₆PSe₅I, respectively. The reported band gaps for Ag₆PSe₅X (X = Cl, Br, and I) compounds are in the visible region. To describe how light interacts with the materials, the optical characteristics of all three materials are reported for photon energies in the range 0 and 12 eV. The computed optical values reveal that the materials are appropriate concerning application in optical-electronic equipments operating in this spectral area owing to their semiconducting features and significant absorption peaks in the UV energy spectrum. The ductile behavior of the three materials is revealed by their mechanical characteristics. The Debye temperatures for Ag₆PSe₅Cl, Ag₆PSe₅Br, and Ag₆PSe₅I are 490.80 K, 332.65 K, and 104.27 K, respectively. Thermoelectric parameters of p-type semiconductors with a positive Seebeck coefficient and low thermal conductivity were, suggesting that these semiconductors possess the potential for usage in thermoelectric applications.