DFT study of optoelectronic and magnetic properties of a novel type perovskites

Using density functional theory, we study the electronic properties of a novel BaHx-6OxTe (where x = 4, 5, 6 or 8) and Ba5Nb4-xTaxO15 (where x = 0, 1, 2, 3 or 4) type perovskites, which are very promising for optoelectronic devices. Further, we investigate the magnetic properties and the optical response spectra such as dielectric function, absorption coefficient, conductivity, and a refractive index of these perovskites. The calculated results show that the predicted geometry can well reproduce the structural parameters, where an excellent agreement was obtained between the calculated and experimental results. Our calculations indicate that the band gap at the high symmetry points can be tuned in a large range of 0.254-4.312 eV with a different magnetic order. The incorporation of Hx-6 into BaOxTe system gives a wide band gap semiconductor, which is shown by first-principles electronic-structure calculations of band structures with a ferromagnetic order.