In this work, the structural, electronic, elastic, thermodynamic, optical, and thermoelectric properties of cubic Barium titanate (BaTiO 3 ) are systematically investigated using ab initio density functional theory. Structural optimizations using the Murnaghan equation of state yields an equilibrium lattice constants of a = b = c 4.01 Å and a bulk modulus of B = 178.3 GPa, which is in close agreement with previous theoretical reports. Electronic band-structure calculations reveal a wide band gap of 1.862 eV, confirming the semiconducting nature of cubic phase of Barium titanate. Elastic constants satisfy the Born stability criteria, indicating mechanical stability, while phonon dispersion curves show no imaginary frequencies, confirming dynamical stability. Optical analysis demonstrates strong absorption in the ultraviolet and visible regions with absorption coefficients exceeding 1 0 4 – 1 0 5 c m − 1 , arising mainly from O–2p to Ti–3d transitions. The Debye temperature ( θ D = 615.76K) and heat capacity behavior indicate good thermal reliability under solar operating conditions. Furthermore, the calculated Seebeck coefficient and low lattice thermal conductivity suggest moderate thermoelectric potential at elevated temperatures. These results highlight cubic Barium titanate as a mechanically robust and optically active oxide with potential applications in ferroelectric photovoltaics, optoelectronics, and energy-conversion devices. • PBEsol technique effectively predicted band gap of 1.862eV for BaTiO 3 • The material has a direct band. • The material exhibits a broad spectrum ranging from 4eV to 18eV, with major peaks appearing within the visible and UV regions.
MUASYA et al. (Sun,) studied this question.