Direct Observation of Electrostatically Driven Band Gap Renormalization in a Degenerate Perovskite Transparent Conducting Oxide

Z Lebens-Higgins; D O Scanlon; H Paik; S Sallis; Y Nie; M Uchida; N F Quackenbush; M J Wahila; G E Sterbinsky; Dario A Arena; J C Woicik; D G Schlom; L F J Piper

doi:10.1103/PhysRevLett.116.027602

Direct Observation of Electrostatically Driven Band Gap Renormalization in a Degenerate Perovskite Transparent Conducting Oxide

Phys Rev Lett. 2016 Jan 15;116(2):027602. doi: 10.1103/PhysRevLett.116.027602. Epub 2016 Jan 15.

Authors

Z Lebens-Higgins¹, D O Scanlon², H Paik³, S Sallis⁴, Y Nie^{3

5}, M Uchida^{5

6}, N F Quackenbush¹, M J Wahila¹, G E Sterbinsky⁷, Dario A Arena⁸, J C Woicik⁹, D G Schlom^{3

10}, L F J Piper^{1

4}

Affiliations

¹ Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, 10 New York 13902, USA.
² Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom.
³ Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
⁴ Materials science and Engineering, Applied Physics and Astronomy, Binghamton University, Binghamton, 10 New York 13902, USA.
⁵ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA‡
⁶ Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.
⁷ National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA§
⁸ National Synchrotron Light Source-II, Basic Energy Sciences Directorate, Brookhaven National Laboratory, Upton, New York 11973, USA¶
⁹ Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
¹⁰ Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States.

PMID: 26824566
DOI: 10.1103/PhysRevLett.116.027602

Abstract

We have directly measured the band gap renormalization associated with the Moss-Burstein shift in the perovskite transparent conducting oxide (TCO), La-doped BaSnO_{3}, using hard x-ray photoelectron spectroscopy. We determine that the band gap renormalization is almost entirely associated with the evolution of the conduction band. Our experimental results are supported by hybrid density functional theory supercell calculations. We determine that unlike conventional TCOs where interactions with the dopant orbitals are important, the band gap renormalization in La-BaSnO_{3} is driven purely by electrostatic interactions.