The effective barrier height between an electrode and a ferroelectric (FE) depends on both macroscopic electrical properties and microscopic chemical and electronic structure. The behavior of a prototypical electrode/FE/electrode structure, Pt/BaTiO3/Nb-doped SrTiO3, under in-situ bias voltage is investigated using X-Ray Photoelectron Spectroscopy. The full band alignment is measured and is supported by transport measurements. Barrier heights depend on interface chemistry and on the FE polarization. A differential response of the core levels to applied bias as a function of the polarization state is observed, consistent with Callen charge variations near the interface.
@article{arxiv.1302.4603,
title = {Interface Electronic Structure in a Metal/Ferroelectric Heterostructure under Applied Bias},
author = {J. E. Rault and G. Agnus and T. Maroutian and V. Pillard and Ph. Lecoeur and G. Niu and B. Vilquin and M. G. Silly and A. Bendounan and F. Sirotti and N. Barrett},
journal= {arXiv preprint arXiv:1302.4603},
year = {2013}
}