Schottky barrier height and conduction mechanisms in ferroelectric bismuth titanate

摘要

Band structure of ferroelectric bismuth titanate is calculated by first-principles computations under the framework of density functional theory. Using the metal induced gap state model, the Schottky barrier height on Pt electrode is estimated to be as high as 1.26 eV, which indicates that the Schottky effect may not be the dominant conduction mechanism in bismuth titanate. By further comparisons with the experimental data, we conclude that the leakage current behavior of bismuth titanate films is dominated by bulk limited conduction mechanisms and can be reduced by better processing conditions or doping.