New findings on a Zintl phased K₃Ag₃As₂ ternary semiconductor compound for photovoltaic applications by first-principles methods

A Zintl-phased K3Ag3As2 ternary compound previously not studied using ab initio techniques was analysed for its structural, electronic, mechanical, elastic, and optical properties using LDA-PZ, GGA-EV, GGA-PBE, GGA-PBESol, GGA-revPBE, and SO-GGA as the exchange correlation functionals. The structural property calculations showed that the material adopts a rhombohedral crystal structure with a mean lattice parameter of 15.1808 a.u. The material has been found to have a direct bandgap where the lowest value has been found to be 1.07 eV while the highest value was 1.74 eV when using PZ-LDA and EV-GGA, respectively. The density of states calculations have shown that the valence band formation is dominated by orbitals As 2p and Ag 3d, whereas the conduction band is mainly formed through the hybridisation of Ag 2p and As 2p orbitals. This material has been found to be mechanically stable and ductile and has ionic bonding. The optical property calculations have shown that it is suitable for optoelectronic applications. The obtained values have been found to be consistent with the experimental values obtained previously.