Please use this identifier to cite or link to this item: https://doi.org/10.1103/PhysRevX.3.021010
DC FieldValue
dc.titleOrigin of the Two-Dimensional Electron Gas at LaAlO3=SrTiO3 Interfaces: The Role of Oxygen Vacancies and Electronic Reconstruction
dc.contributor.authorLiu, Z.Q.
dc.contributor.authorLi, C.J.
dc.contributor.authorLü, W.M.
dc.contributor.authorHuang, X.H.
dc.contributor.authorHuang, Z.
dc.contributor.authorZeng, S.W.
dc.contributor.authorQiu, X.P.
dc.contributor.authorHuang, L.S.
dc.contributor.authorAnnadi, A.
dc.contributor.authorChen, J.S.
dc.contributor.authorCoey, J.M.D.
dc.contributor.authorVenkatesan, T.
dc.contributor.authorAriando
dc.date.accessioned2014-10-07T04:34:16Z
dc.date.available2014-10-07T04:34:16Z
dc.date.issued2013
dc.identifier.citationLiu, Z.Q., Li, C.J., Lü, W.M., Huang, X.H., Huang, Z., Zeng, S.W., Qiu, X.P., Huang, L.S., Annadi, A., Chen, J.S., Coey, J.M.D., Venkatesan, T., Ariando (2013). Origin of the Two-Dimensional Electron Gas at LaAlO3=SrTiO3 Interfaces: The Role of Oxygen Vacancies and Electronic Reconstruction. Physical Review X 3 (2) : -. ScholarBank@NUS Repository. https://doi.org/10.1103/PhysRevX.3.021010
dc.identifier.issn21603308
dc.identifier.urihttp://scholarbank.nus.edu.sg/handle/10635/82853
dc.description.abstractThe relative importance of atomic defects and electron transfer in explaining conductivity at the crystalline LaAlO3=SrTiO3 interface has been a topic of debate. Metallic interfaces with similar electronic properties produced by amorphous oxide overlayers on SrTiO3 [Y. Chen et al., Nano Lett. 11, 3774 (2011); S.W. Lee et al., Nano Lett. 12, 4775 (2012)] have called in question the original polarization catastrophe model [N. Nakagawa et al., Nature Mater. 5, 204 (2006)]. We resolve the issue by a comprehensive comparison of (100)-oriented SrTiO3 substrates with crystalline and amorphous overlayers of LaAlO3 of different thicknesses prepared under different oxygen pressures. For both types of overlayers, there is a critical thickness for the appearance of conductivity, but its value is always 4 unit cells (around 1.6 nm) for the oxygen-annealed crystalline case, whereas in the amorphous case, the critical thickness could be varied in the range 0.5 to 6 nm according to the deposition conditions. Subsequent ion milling of the overlayer restores the insulating state for the oxygen-annealed crystalline heterostructures but not for the amorphous ones. Oxygen post-annealing removes the oxygen vacancies, and the interfaces become insulating in the amorphous case. However, the interfaces with a crystalline overlayer remain conducting with reduced carrier density. These results demonstrate that oxygen vacancies are the dominant source of mobile carriers when the LaAlO3 overlayer is amorphous, while both oxygen vacancies and polarization catastrophe contribute to the interface conductivity in unannealed crystalline LaAlO3=SrTiO3 heterostructures, and the polarization catastrophe alone accounts for the conductivity in oxygen-annealed crystalline LaAlO3=SrTiO3 heterostructures. Furthermore, we find that the crystallinity of the LaAlO3 layer is crucial for the polarization catastrophe mechanism in the case of crystalline LaAlO3overlayers.
dc.description.urihttp://libproxy1.nus.edu.sg/login?url=http://dx.doi.org/10.1103/PhysRevX.3.021010
dc.sourceScopus
dc.typeArticle
dc.contributor.departmentELECTRICAL & COMPUTER ENGINEERING
dc.contributor.departmentPHYSICS
dc.contributor.departmentMATERIALS SCIENCE AND ENGINEERING
dc.description.doi10.1103/PhysRevX.3.021010
dc.description.sourcetitlePhysical Review X
dc.description.volume3
dc.description.issue2
dc.description.page-
dc.identifier.isiut000319739000002
Appears in Collections:Staff Publications

Show simple item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

259
checked on Jan 27, 2023

WEB OF SCIENCETM
Citations

261
checked on Jan 19, 2023

Page view(s)

157
checked on Jan 26, 2023

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.