Pb-free Semiconductor Ferroelectrics: A Theoretical Study of Pd-substituted Ba(Ti\u3csub\u3e1-\u3cem\u3ex\u3c/em\u3e\u3c/sub\u3eCe\u3csub\u3e\u3cem\u3ex\u3c/em\u3e\u3c/sub\u3e)O\u3csub\u3e3\u3c/sub\u3e Solid Solutions

Abstract

We use first-principles density-functional-theory calculations to investigate the ground state structures of Ba(Ti1−xCex)O3 solid solutions containing Pd. Previous studies have shown that the properties of BaTiO3, a Pb-free ferroelectric ABO3 perovskite, can be tailored via B-site substitution. In the present study, we substitute Ce for Ti to increase the overall volume of the perovskite, to then accommodate an O-vacancy-stabilized Pd substitution. Using the LDA+U method, we predict that these proposed materials will display a decreased band gap compared to BaTiO3 while maintaining polarization. These features, combined with their environmentally friendly characteristics make these materials promising candidates for use as semiconducting ferroelectrics in solar-energy conversion devices