Effect of lithium diffusion into Ga 2 O 3 thin films

Sacchi, A. [Univ. of Parma (Italy)]; Sidoli, M. [Univ. of Parma (Italy)] (ORCID:0000000251827038); Ardenghi, A. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)] (ORCID:0000000249871873); Bierwagen, O. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)]; Kler, J. [RWTH Aachen Univ. (Germany)]; Falkenstein, A. [RWTH Aachen Univ. (Germany)] (ORCID:0000000249920823); De Souza, R. A. [RWTH Aachen Univ. (Germany)]; Martin, M.; Spallek, D. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)]; Lähnemann, J. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)]; Tornatzky, H. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)] (ORCID:0000000231530501); Wagner, M. R. [Leibniz-Institut im Forschungsverbund, Berlin (Germany); Technical Univ. of Berlin (Germany)] (ORCID:0000000273675629); Parisini, A. [Univ. of Parma (Italy)] (ORCID:0000000342125074); Pavesi, M. [Univ. of Parma (Italy)] (ORCID:0000000229190106); Bosi, M. [National Research Council (CNR) (Italy)]; Seravalli, L. [National Research Council (CNR) (Italy)] (ORCID:0000000327841785); Varley, J. B. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000253845248); Spaggiari, G. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)]; Bersani, D. [Univ. of Parma (Italy)]; Mizohata, K. [Univ. of Helsinki (Finland)]; Tuomisto, F. [Univ. of Helsinki (Finland)]; Magnani, G. [Univ. of Parma (Italy)] (ORCID:0000000289709125); Pontiroli, D. [Univ. of Parma (Italy)]; Riccò, M. [Univ. of Parma (Italy)]; Mezzadri, F. [National Research Council (CNR) (Italy); Univ. of Parma (Italy)] (ORCID:0000000195051457); Pasini, S. [Univ. of Parma (Italy)] (ORCID:0000000239098848); Bosio, A. [Univ. of Parma (Italy)]; Fornari, R. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)] (ORCID:0000000244998015); Mazzolini, P. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)] (ORCID:0000000320925265)

doi:10.1016/j.apsusc.2025.163974

DOE OSTI · 2998667

Effect of lithium diffusion into Ga 2 O 3 thin films

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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-Ga2O3 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 (VGa). 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 -nLi complexes).

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Defects Diffusion Epitaxial growth Semiconductors Ultra-wide bandgap oxides

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Sacchi, A. [Univ. of Parma (Italy)], Sidoli, M. [Univ. of Parma (Italy)] (ORCID:0000000251827038), Ardenghi, A. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)] (ORCID:0000000249871873), Bierwagen, O. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)], Kler, J. [RWTH Aachen Univ. (Germany)], Falkenstein, A. [RWTH Aachen Univ. (Germany)] (ORCID:0000000249920823), De Souza, R. A. [RWTH Aachen Univ. (Germany)], Martin, M., Spallek, D. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)], Lähnemann, J. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)], Tornatzky, H. [Leibniz-Institut im Forschungsverbund, Berlin (Germany)] (ORCID:0000000231530501), Wagner, M. R. [Leibniz-Institut im Forschungsverbund, Berlin (Germany); Technical Univ. of Berlin (Germany)] (ORCID:0000000273675629), Parisini, A. [Univ. of Parma (Italy)] (ORCID:0000000342125074), Pavesi, M. [Univ. of Parma (Italy)] (ORCID:0000000229190106), Bosi, M. [National Research Council (CNR) (Italy)], Seravalli, L. [National Research Council (CNR) (Italy)] (ORCID:0000000327841785), Varley, J. B. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000253845248), Spaggiari, G. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)], Bersani, D. [Univ. of Parma (Italy)], Mizohata, K. [Univ. of Helsinki (Finland)], Tuomisto, F. [Univ. of Helsinki (Finland)], Magnani, G. [Univ. of Parma (Italy)] (ORCID:0000000289709125), Pontiroli, D. [Univ. of Parma (Italy)], Riccò, M. [Univ. of Parma (Italy)], Mezzadri, F. [National Research Council (CNR) (Italy); Univ. of Parma (Italy)] (ORCID:0000000195051457), Pasini, S. [Univ. of Parma (Italy)] (ORCID:0000000239098848), Bosio, A. [Univ. of Parma (Italy)], Fornari, R. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)] (ORCID:0000000244998015), Mazzolini, P. [Univ. of Parma (Italy); National Research Council (CNR) (Italy)] (ORCID:0000000320925265). 2025-07-04. Effect of lithium diffusion into Ga 2 O 3 thin films. https://doi.org/10.1016/j.apsusc.2025.163974

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