Effect of oxygen vacancies in the SrTiO3 substrate on the electrical properties of the LaAlO3/SrTiO3 interface
Journal article, 2007
We experimentally investigated optical, electrical, and microstructural properties of heterointerfaces between two thin-film perovskite insulating materials, SrTiO3 (STO) and LaAlO3 (LAO), deposited at different oxygen pressure conditions. Cathode and photoluminescence experiments show that oxygen vacancies are formed in the bulk STO substrate during the growth of LAO films, resulting in high electrical conductivity and mobility values. In both high and low oxygen pressure interfaces, the electrical Hall mobilities follow a similar power-law dependence as observed in oxygen reduced STO bulk samples. The results are confirmed on a microscopic level by local strain fields at the interface reaching 10 nm into the STO substrate.
substrates
lanthanum compounds
strontium compounds
photoluminescence
Hall mobility
crystal microstructure
interface structure
cathodoluminescence
insulating thin films
vacancies (crystal)
electrical conductivity
Author
Alexei Kalaboukhov
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Robert Gunnarsson
Chalmers, Microtechnology and Nanoscience (MC2)
Johan Börjesson
Chalmers, Applied Physics, Microscopy and Microanalysis
Eva Olsson
Chalmers, Applied Physics, Microscopy and Microanalysis
Dag Winkler
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Tord Claeson
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Physical Review B - Condensed Matter and Materials Physics
24699950 (ISSN) 24699969 (eISSN)
Vol. 75 12 121404R-Subject Categories
Condensed Matter Physics