Origin of Charge Density at ${\mathrm{LaAlO}}_3$ on ${\mathrm{SrTiO}}_3$ Heterointerfaces: Possibility of Intrinsic Doping

Journal Article · Tue May 01 00:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.98.196802· OSTI ID:908755

Siemons, Wolter; Koster, Gertjan; Yamamoto, Hideki; Harrison, Walter A.; Lucovsky, Gerald; Geballe, Theodore H.; Blank, Dave H. A.; Beasley, Malcolm R.

As discovered by Ohtomo and Hwang, a large sheet charge density with high mobility exists at the interface between SrTiO{sub 3} and LaAlO{sub 3}. Based on transport, spectroscopic, and oxygen-annealing experiments, we conclude that extrinsic defects in the form of oxygen vacancies introduced by the pulsed laser deposition process used by all researchers to date to make these samples is the source of the large carrier densities. Annealing experiments show a limiting carrier density. We also present a model that explains the high mobility based on carrier redistribution due to an increased dielectric constant.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 908755
• Report Number(s): SLAC-PUB-12540; PRLTAO; TRN: US200722%%773
• Journal Information: Physical Review Letters, Vol. 98, Issue 19; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARGE DENSITY
INTERFACES
STRONTIUM OXIDES
TITANIUM OXIDES
LANTHANUM OXIDES
ALUMINIUM OXIDES
CARRIER DENSITY
ANNEALING
MATHEMATICAL MODELS
CARRIER MOBILITY
Other
SYNCHRAD