Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces

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.

References in corpus (11)

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• Growth mode control of the free carrier density in SrTiO3-d films
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• Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides
• Charge ordering and magnetism in quarter-filled Hubbard-Holstein model

Cited by in corpus (15)

• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
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• Surface defects and conduction in polar oxide heterostructures
• Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction
• Band alignment and charge transfer in complex oxide interfaces
• Electronic reconstruction at the isopolar LaTiO3/LaFeO3 interface: An x-ray photoemission and density functional theory study
• Polar catastrophe in ultra-thin limit: A case of rare-earth perovskite LaNiO3
• Localized versus itinerant states created by multiple oxygen vacancies in SrTiO3
• Prediction of thickness limits of ideal polar ultrathin films
• Competition between covalent bonding and charge transfer at complex-oxide interfaces
• Appearance and disappearance of ferromagnetism in ultra-thin LaMnO${}_3$ on SrTiO${}_3$ substrate: a viewpoint from first-principles
• Temperature-Dependent Band Structure of SrTiO${}_3$ Interfaces
• Anomalous transport near the Lifshitz transition at the LaAlO${}_3$/SrTiO${}_3$ interface
• La interstitial defect-induced insulator-metal transition in oxide heterostructures LaAlO3/SrTiO3
• Large electropositive cations as surfactants for the growth of polar epitaxial films