Band offsets in complex-oxide thin films and heterostructures of SrTiO3/LaNiO3 and SrTiO3/GdTiO3 by soft and hard X-ray photoelectron spectroscopy
Abstract
The experimental determination of valence band offsets (VBOs) at interfaces in complex-oxide heterostructures using conventional soft x-ray photoelectron spectroscopy (SXPS, hν ≤ 1500 eV) and reference core-level binding energies can present challenges because of surface charging when photoelectrons are emitted and insufficient probing depth to clearly resolve the interfaces. In this paper, we compare VBOs measured with SXPS and its multi-keV hard x-ray analogue (HXPS, hν > 2000 eV). We demonstrate that the use of HXPS allows one to minimize charging effects and to probe more deeply buried interfaces in heterostructures such as SrTiO3/LaNiO3 and SrTiO3/GdTiO3. The VBO values obtained by HXPS for these interfaces are furthermore found to be close to those determined by first-principles calculations.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 08, 2013
- Source ID
- 10.1063/1.4795612
Entities
People
- A. A. Greer
- A. Bostwick
- A. Gloskovskii
- A. Janotti
- A. Keqi
- A. M. Kaiser
- A. Rattanachata
- A. X. Gray
- A. Y. Saw
- C. G. Van De Walle
- C. M. Schneider
- C. S. Conlon
- C. S. Fadley
- D. Eiteneer
- G. K. Palsson
- Galen Conti
- J. Son
- K. Kobayashi
- L. Bjaalie
- M. Kobata
- Pouya Moetakef
- S. Nemšák
- S. Stemmer
- S. Ueda
- W. C. Stolte
- W. Drube
Organizations
- Advanced Light Source
- Army Research Office
- DESY
- Lawrence Berkeley National Laboratory
- National Science Foundation
- SLAC National Accelerator Laboratory
- United States Department of Energy
- University of California