This title appears in the Scientific Report :
2019
Please use the identifier:
http://hdl.handle.net/2128/22132 in citations.
Please use the identifier: http://dx.doi.org/10.1103/PhysRevMaterials.3.044604 in citations.
Chemical control of the electrical surface properties in donor-doped transition metal oxides
Chemical control of the electrical surface properties in donor-doped transition metal oxides
Donor-doped transition metal oxides such as donor-doped strontium titanate (n−SrTiO3) are of fundamental importance for oxide electronic devices as well as for electronic surface and interface engineering. Here we quantitatively analyze the variable band alignment and the resulting space charge laye...
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Personal Name(s): | Andrä, M. (Corresponding author) |
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Bluhm, H. / Dittmann, R. / Schneider, Claus Michael / Waser, R. / Müller, David / Gunkel, F. | |
Contributing Institute: |
Elektronische Materialien; PGI-7 Elektronische Eigenschaften; PGI-6 JARA Institut Quanteninformation; PGI-11 JARA-FIT; JARA-FIT |
Published in: | Physical review materials, 3 (2019) 4, S. 044604 |
Imprint: |
College Park, MD
APS
2019
|
DOI: |
10.1103/PhysRevMaterials.3.044604 |
Document Type: |
Journal Article |
Research Program: |
Controlling Collective States |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1103/PhysRevMaterials.3.044604 in citations.
Donor-doped transition metal oxides such as donor-doped strontium titanate (n−SrTiO3) are of fundamental importance for oxide electronic devices as well as for electronic surface and interface engineering. Here we quantitatively analyze the variable band alignment and the resulting space charge layer at the surface of n−SrTiO3, determined by its surface redox chemistry. Synchrotron-based ambient-pressure x-ray photoelectron spectroscopy conducted under applied thermodynamic bias is used to access electronic structure and chemistry of the surface. We find an electron depletion layer driven by cationic surface point defects that are controlled by adjusting the ambient atmosphere (pO2). We correlate the pO2 dependence to a response of the strontium sublattice, namely the precipitation of strontium oxide and the formation of charged strontium vacancies at the surface. We suggest the reversible conversion of surface-terminating strontium oxide into extended strontium oxide clusters as the responsible process by resolving chemical dynamics in situ. As we show, atomic control of these subtle changes in the surface redox chemistry allows us to tailor electrical transport properties along the n−SrTiO3 surface. Our study thereby gives access to engineering electronic band bending in transition metal oxides by the control of the surface chemistry. |