Ferroelectric barium titanate derivatives containing Mo and Mg for transparent photovoltaic applications

Using first-principles methods, we investigate the electronic properties of the [Ba(Mo 1 / 2,Mg 1 / 2)O 3] x-[BaTiO 3] 1 - x solid solution derived from barium titanate as a potential candidate to be used in photovoltaic devices. Focusing on the bandgap and its origin, we study the effect of different possible Mo and Mg contents, arrangements, and phases of [Ba(Mo 1 / 2,Mg 1 / 2)O 3] x-[BaTiO 3] 1 - x. We find that [Ba(Mo 1 / 2,Mg 1 / 2)O 3] 0.25-[BaTiO 3] 0.75 is a viable candidate for use in transparent photovoltaics due to its energy bandgap of 2.6 eV in the rhombohedral phase. In all cases, [Ba(Mo 1 / 2,Mg 1 / 2)O 3] x-[BaTiO 3] 1 - x materials exhibit spontaneous polarization that allows the exploitation of the bulk photovoltaic effect and in principle may allow high power conversion efficiency exceeding the Shockley-Queisser limit for these materials.