A combined density functional (PBE, WC and Tb-mBJ) study about the optoelectronic properties of copper-rich ternary chalcogenide materials

Abstract

Here, we thoroughly studied the ground state structural, electronic and optical properties of high crystalline type cubic ACu3Se4 (A = Ta, Nb and V) ternary chalcogenide materials. The the FP-LAPW method within the framework of density functional theory is employed. The electronic structure calculations are treated with highly accurate modified-Becke-Johnson potential to yield the exact band gap values along with the use of Perdew-Burke-Ernzerhof and Wu-Cohen generalized gradient approximation approach for the corresponding optical properties. The band structures and density of states for the three materials are compared and discussed in detail. The complex optical dielectric function’s and the related optical parameters like the absorption coefficient, reflectivity, energy loss function refractive indices and extension coefficient were calculated and discussed in detail for radiations up to energy value of 14 eV. The calculated optical properties display a significant anisotropy between the two components. We further studied the inter-band contributions for the optical characteristics in these ternary chalcogenides. Our described results could pave the way towards further fundamental investigations of the optoelectronic properties of these direct band gap semiconductors in nanoscale regime for solar energy harvesting.