Electronic charges and electric potential at LaAlO3/SrTiO3 interfaces studied by core-level photoemission spectroscopy

Abstract

We studied LaAlO3/SrTiO3 interfaces for varying LaAlO3 thickness by core-level photoemission spectroscopy. In Ti 2p spectra for conducting "n-type" interfaces, Ti3+ signals appeared, which were absent for insulating "p-type" interfaces. The Ti3+ signals increased with LaAlO3 thickness, but started well below the critical thickness of 4 unit cells for metallic transport. Core-level shifts with LaAlO3 thickness were much smaller than predicted by the polar catastrophe model. We attribute these observations to surface defects/adsorbates providing charges to the interface even below the critical thickness.

References in corpus (11)

• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Built-in and induced polarization across LaAlO${}_3$/SrTiO${}_3$ heterojunctions
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• Surface defects and conduction in polar oxide heterostructures
• Origin of Metallic States at Heterointerface between Band Insulators LaAlO${}_3$ and SrTiO${}_3$
• Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices
• Electronic properties of buried hetero-interfaces of LaAlO3 on SrTiO3
• Modulation Doping of a Mott Quantum Well by a Proximate Polar Discontinuity
• Hard x-ray photoemission study of LaAlO3/LaVO3 multilayers
• Electronic Interface Reconstruction at Polar-Nonpolar Mott Insulator Heterojunctions

Cited by in corpus (22)

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• Control of electronic conduction at an oxide heterointerface using surface polar adsorbates
• Origin of two-dimensional electron gases at oxide interfaces: insights from theory
• Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
• Hard x-ray photoemission and density functional theory study of the internal electric field in SrTiO3/LaAlO3 oxide heterostructures
• Band offsets and density of Ti3+ states probed by X-ray photoemission on LaAlO3/SrTiO3 heterointerfaces and their LaAlO3 and SrTiO3 bulk precursors
• Tuning up or down the critical thickness in LaAlO3/SrTiO3 through in situ deposition of metal overlayers
• Enhanced two dimensional electron gas charge densities at III-III/I-V oxide heterostructure interfaces
• Interface-induced Polarization in SrTiO${}_3$-LaCrO${}_3$ Superlattices
• Origin of interfacial conductivity at complex oxide heterointerfaces: possibility of electron transfer from water chemistry at surface oxygen vacancies
• Thickness Dependent Carrier Density at the Surface of SrTiO3 (111) Slabs
• Termination control of electronic phases in oxide thin films and interfaces: LaAlO3/SrTiO3(001)
• Electronic charge redistribution in LaAlO${}_3$(001) thin films deposited at SrTiO${}_3$(001) substrate: First principles analysis and the role of stoichiometry
• Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Probing Quantum Confinement and Electronic Structure at Polar Oxide Interfaces
• Observation of strontium segregation in LaAlO${}_3$/SrTiO${}_3$ and NdGaO${}_3$/SrTiO${}_3$ oxide heterostructures by X-ray photoemission spectroscopy
• Unexpected Termination Switching and Polarity Compensation in LaAlO3/SrTiO3 heterostructures
• In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure
• Polarity-field driven conductivity in SrTiO${}_3$/LaAlO${}_3$: a hybrid functional study
• Coupling between tilts and charge carriers at polar-nonpolar perovskite interfaces