Polarity-induced oxygen vacancies at LaAlO3∕SrTiO3 interfaces

Zhong, ZhiCheng and Xu, P.X. and Kelly, Paul J. (2010) Polarity-induced oxygen vacancies at LaAlO3∕SrTiO3 interfaces. Physical Review B: Condensed matter and materials physics, 82 (16). p. 165127. ISSN 1098-0121

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Abstract:	Using first-principles density-functional-theory calculations, we find a strong position and thickness dependence of the formation energy of oxygen vacancies in LaAlO3∣SrTiO3 (LAO∣STO) multilayers and interpret this with an analytical capacitor model. Oxygen vacancies are preferentially formed at p-type SrO∣AlO2 rather than at n-type LaO∣TiO2 interfaces; the excess electrons introduced by the oxygen vacancies reduce their energy by moving to the n-type interface. This asymmetric behavior makes an important contribution to the conducting (insulating) nature of n-type (p-type) interfaces while providing a natural explanation for the failure to detect evidence for the polar catastrophe in the form of core level shifts
Item Type:	Article
Copyright:	© 2010 The American Physical Society
Faculty:	Science and Technology (TNW)
Research Group:	Computational Materials Science (CMS)
Link to this item:	http://purl.utwente.nl/publications/78143
Official URL:	http://dx.doi.org/10.1103/PhysRevB.82.165127
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