Origin and distribution of charge carriers in LaAlO3-SrTiO3 oxide heterostructures in the high carrier density limit
2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 24, 245124Article in journal (Refereed) PublishedText
Using hard x-ray photoelectron spectroscopywith variable photon energy (2-8 keV), we address the distribution of charge carriers in the prototypical LaAlO3 (LAO) and SrTiO3 (STO) oxide heterostructures with high carrier densities (10(17) cm(-2)). Our results demonstrate the presence of two distinct charge distributions in this system: one tied to the interface with a similar to 1-nm width and similar to 2-5 x 10(14)-cm(-2) carrier concentration, while the other appears distributed nearly homogeneously through the bulk of STO corresponding to a much larger carrier contribution. Our results also establish bimodal oxygen vacancies, namely on top of LAO and throughout STO, quantitatively establishing these as the origin of the observed bimodal depth distribution of charge carriers in these highly doped sample.
Place, publisher, year, edition, pages
2016. Vol. 93, no 24, 245124
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-299039DOI: 10.1103/PhysRevB.93.245124ISI: 000377500000003OAI: oai:DiVA.org:uu-299039DiVA: diva2:948809
FunderThe Swedish Foundation for International Cooperation in Research and Higher Education (STINT)