Polarity-induced oxygen vacancies at LaAl3/SrTiO3 interfaces

Zhicheng Zhong, P.X. Xu, Paul J. Kelly

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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
Original languageUndefined
Pages (from-to)165127/1-165127/5
Number of pages5
JournalPhysical review B: Condensed matter and materials physics
Volume82
Issue number16
DOIs
Publication statusPublished - 2010

Keywords

  • METIS-268790
  • IR-78143

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