Journal of Materials Science

, Volume 54, Issue 6, pp 4780–4787 | Cite as

Highly conductive two-dimensional electron gas at the interface of Al2O3/SrTiO3

  • Zhaoting Zhang
  • Hong Yan
  • Shuanhu Wang
  • Min Wang
  • Lixia Ren
  • Changle Chen
  • Kexin JinEmail author
Electronic materials


We create a two-dimensional electron gas at the Al2O3/SrTiO3/LaAlO3 heterostructures using pulsed laser deposition, which exhibits a decreasing sheet resistance with increasing growth temperatures of Al2O3 films. Structural characterizations of films are confirmed by cross-sectional transmission electron microscopy. Compared with these heterostructures with Al2O3 films deposited on pristine SrTiO3 and TiO2-terminated SrTiO3 substrates, the Al2O3/SrTiO3/LaAlO3 heterostructures are more conductive. X-ray photoelectron spectroscopy indicates the formation of oxygen vacancies at the SrTiO3 side of the interface, which results from the redox reactions by reducing SrTiO3 films. Furthermore, the existence of oxygen vacancies on the SrTiO3 side is verified by a blue-light emission.



This work is supported by the National Natural Science Foundation of China (Nos. 51572222, 51172183 and 61471301).

Compliance with ethical standards

Conflict of interest

The authors declare no competing financial interest.


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Shaanxi Key Laboratory of Condensed Matter Structures and Properties, School of Natural and Applied SciencesNorthwestern Polytechnical UniversityXi’anChina

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