Hard x-ray photoemission spectroscopy of LaVO3/SrTiO3 : Band alignment and electronic reconstruction

DOI: 10.1103/PhysRevB.103.235128

Authors: M. Stübinger (Universität Würzburg) , J. Gabel (Universität Würzburg; Diamond Light Source) , Philipp Scheiderer (Universität Würzburg) , M. Zapf (Universität Würzburg) , M. Schmitt (Universität Würzburg) , P. Schütz (Universität Würzburg) , B. Leikert (Universität Würzburg) , J. Küspert (Universität Würzburg) , M. Kamp (Universität Würzburg) , P. K. Thakur (Diamond Light Source) , T.-L. Lee (Diamond Light Source) , P. Potapov (Leibniz Institute for Solid State and Materials Research and Würzburg-Dresden Cluster of Excellence ct.qmat) , A. Lubk (Leibniz Institute for Solid State and Materials Research and Würzburg-Dresden Cluster of Excellence ct.qmat) , B. Büchner (Leibniz Institute for Solid State and Materials Research and Würzburg-Dresden Cluster of Excellence ct.qmat) , M. Sing (Universität Würzburg) , R. Claessen (Universität Würzburg)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 103

State: Published (Approved)
Published: June 2021
Diamond Proposal Number(s): 17499 , 23737

Abstract: A heterostructure consisting of the Mott insulator LaVO3 and the band insulator SrTiO3 is considered a promising candidate for future photovoltaic applications. Not only does the (direct) excitation gap of LaVO3 match well the solar spectrum, but its correlated nature and predicted built-in potential, owing to the nonpolar/polar interface when integrated with SrTiO3, also offer remarkable advantages over conventional solar cells. However, experimental data beyond the observation of a thickness-dependent metal-insulator transition are scarce and a profound, microscopic understanding of the electronic properties is still lacking. By means of soft and hard x-ray photoemission spectroscopy as well as resistivity and Hall effect measurements we study the electrical properties, band bending, and band alignment of LaVO3/SrTiO3 heterostructures. We find a critical LaVO3 thickness of five unit cells, confinement of the conducting electrons to exclusively Ti 3d states at the interface, and a potential gradient in the film. From these findings we conclude on electronic reconstruction as the driving mechanism for the formation of the metallic interface in LaVO3/SrTiO3.

Journal Keywords: Electrical conductivity; Electronic structure; Metal-insulator transition; Photovoltaic absorbers; Strongly correlated systems; Transition-metal oxides; X-ray photoelectron spectroscopy

Diamond Keywords: Photovoltaics; Semiconductors; Antiferromagnetism

Subject Areas: Physics, Materials, Chemistry


Instruments: I09-Surface and Interface Structural Analysis

Added On: 14/06/2021 18:19

Discipline Tags:

Quantum Materials Earth Sciences & Environment Sustainable Energy Systems Hard condensed matter - electronic properties Energy Physics Climate Change Energy Materials Magnetism Materials Science

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS)