Band gap and Schottky barrier heights of multiferroic BiFeO3

BiFeO3 is an interesting multiferroic oxide and a potentially important Pb-free ferroelectric. However, its applications can be limited by large leakage currents. Its band gap is calculated by the density-functional based screened exchange method to be 2.8 eV, similar to experiment. The Schottky barrier height on Pt or SrRuO3 is calculated in the metal induced gap state model to be over 0.9 eV. Thus, its leakage is not intrinsic. (c) 2007 American Institute of Physics.