Interface electronic structure in a metal/ferroelectric heterostructure under applied bias

J.E. Rault (1) , T. Maroutian (2) , G. Agnus (2) , Ph. Lecoeur (2) , G. Niu (3) , M. G. Silly (4) , B. Vilquin (3) , A. Bendounan (4) , F. Sirotti (4) , N. Barrett (1)

1 SPCSI - Service de Physique et de Chimie des Surfaces et Interfaces
2 IEF - Institut d'électronique fondamentale
3 INL - H&N - INL - Hétéroepitaxie et Nanostructures
4 SSOLEIL - Synchrotron SOLEIL

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/BaTiO$_3$ /Nb-doped SrTiO$_3$ , 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.

Domains: Physics [physics]

J.E. Rault, T. Maroutian, G. Agnus, Ph. Lecoeur, G. Niu, et al.. Interface electronic structure in a metal/ferroelectric heterostructure under applied bias. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 87, pp.155146. ⟨10.1103/PhysRevB.87.155146⟩. ⟨cea-01477666⟩