Effect of lithium diffusion into Ga2O3 thin films

Applied Surface Science, vol. 710, pp. 163974

Abstract

The integration of lithium based compounds ( e.g. , Li:NiO/Ga 2 O 3 , LiGa 5 O 8 /Ga 2 O 3 ) in Ga 2 O 3 based pn -heterojunctions raises concerns about interface stability, i.e. , Li diffusion effects on Ga 2 O 3 properties. In this work the ex-situ diffusion of Li is investigated in three different Ga 2 O 3 epilayers systems [(001) κ-Ga 2 O 3 and (−201) β-Ga 2 O 3 heteroepitaxy on (001) α-Al 2 O 3 , and (010) β-Ga 2 O 3 homoepitaxy] at relevant temperatures for the synthesis / processing of Li-based epilayers. It is here experimentally demonstrated and quantified the Li diffusion in all the investigated Ga 2 O 3 epilayers systems and Li bulk ( D Li,bulk ) and 2D defects ( D Li,2D ) diffusion coefficients are provided. In the case of the (010) β-Ga 2 O 3 homoepitaxial layer (nominally free of structural defects), hybrid functional theory calculations foresee a diffusion mechanism mediated by Ga vacancies (V Ga ). Moreover, in the (010) β-Ga 2 O 3 homo-layer a significant effect on its functional properties ( e.g., additional Raman vibrational modes, induced conductivity in an otherwise insulating sample) upon the Li-diffusion process is experimentally highlighted and tentatively related to the passivation of acceptor defects ( i.e. , formation of V Ga - n Li complexes).

Authors 28

1. Anna Sacchi corresponding

   University of Parma

   Affiliation as printed

   Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

2. Michele Sidoli

   University of Parma

   Affiliation as printed

   Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

3. A. Ardenghi

   Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin

   Affiliation as printed

   Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

4. Oliver Bierwagen

   Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin

   Affiliation as printed

   Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

5. Joe Kler Aachen Institute of Physical Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Chemistry, RWTH Aachen University, Germany

6. Andreas Falkenstein Aachen Institute of Physical Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Chemistry, RWTH Aachen University, Germany

7. Roger A. De Souza
8. Domenik Spallek

   Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin

   Affiliation as printed

   Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

9. Jonas Lähnemann

   Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin

   Affiliation as printed

   Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

10. Hans Tornatzky

    Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin

    Affiliation as printed

    Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

11. Markus R. Wagner

    Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin · Technische Universität Berlin

    Affiliation as printed

    Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany

    Technische Universität Berlin, Institute of Solid State Physics, Berlin, Germany

12. A. Parisini

    University of Parma

    Affiliation as printed

    Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

13. Maura Pavesi

    University of Parma

    Affiliation as printed

    Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

14. Matteo Bosi

    Institute of Materials for Electronics and Magnetism

    Affiliation as printed

    IMEM-CNR, Parma, Italy

15. L. Seravalli

    Institute of Materials for Electronics and Magnetism

    Affiliation as printed

    IMEM-CNR, Parma, Italy

16. Joel Basile Varley

    Lawrence Livermore National Laboratory

    Affiliation as printed

    Lawrence Livermore National Laboratory, Livermore, United States

17. Giulia Spaggiari

    University of Parma · Institute of Materials for Electronics and Magnetism

    Affiliation as printed

    Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

    IMEM-CNR, Parma, Italy

18. Danilo Bersani

    University of Parma

    Affiliation as printed

    Department of Mathematical, Physical and Computer Sciences, University of Parma, Italy

19. Kenichiro Mizohata

    University of Helsinki

    Affiliation as printed

    Department of Physics, University of Helsinki, POB 43, FI-00014 Helsinki, Finland

20. Filip Tuomisto
21. Giacomo Magnani
22. Daniele Pontiroli
23. Mauro Riccò
24. Francesco Mezzadri
25. Stefano Pasini
26. Alessio Bosio
27. R. Fornari
28. Piero Mazzolini corresponding