Electronic, structural and optical properties of BaTiO3 doped with lanthanum (La): Insight from DFT calculation

We have studied the barium titanate (BaTiO3) by using the CASTEP which based on density functional theory (DFT) under the correlation function of GGA and PBE. Material under study has been doped by Lanthanum (La) at the sites of Barium (Ba). Before and after doping we have calculated the different optical, structural and electronic properties and have been discussed in detail. After doping, reduction of band gap is noticed and as well as nature of band gap is also changed from indirect band gap (IBG) to direct band gap (DBG). This variation in band gap has been explained clearly on the behalf of partially and total density of states. Refractive index (n) is 2.598 for pure and 2.482 for doped system. Absorption peak also effected by inclusion of La.