Band alignments of the platinum/SrBi2Ta2O9 interface

In situ x-ray photoelectron spectroscopy was used to determine the band alignments of the platinum to SrBi2Ta2O9 contact. The interfaces were prepared by incremental evaporation of Pt onto a vacuum/O2 annealed polycrystalline surface grown by the sol-gel method. The results track the development of the band alignments from the submonolayer to the thick metal-film regimes. The Fermi level to ferroelectric valence-band offset of the asymptotic full metal contact was found to be 2.9 eV. The contact was also clearly shown to be highly disrupted with a bismuth-platinum alloy forming at the interface.