Gallium Oxide Fabrication with Ion Beams (GoFIB)

• Polyakov, Alexander Y.; Vasilev, Anton A.; Kochkova, Anastasiia I.; Shchemerov, Ivan V.; Yakimov, Eugene B. & Miakonkikh, Andrej V. [Vis alle 17 forfattere av denne artikkelen] (2024). Proton damage effects in double polymorph γ/β-Ga<inf>2</inf>O<inf>3</inf> diodes. Journal of Materials Chemistry C. ISSN 2050-7526. 12, s. 1020–1029. doi: 10.1039/d3tc04171a.
• Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Lee, In-Hwan & Kuznetsov, Andrej (2023). Thermal versus radiation-assisted defect annealing in β-Ga2O3. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. ISSN 0734-2101. 41(2). doi: 10.1116/6.0002388. Fulltekst i vitenarkiv
• Azarov, Alexander; Park, Ji-Hyeon; Jeon, Dae-Woo & Kuznetsov, Andrej (2023). High mobility of intrinsic defects in α-Ga2O3. Applied Physics Letters. ISSN 0003-6951. 122(18), s. 182104-1–182104-4. doi: 10.1063/5.0149870. Fulltekst i vitenarkiv Vis sammendrag

  Migration properties of the intrinsic defects were investigated in α-Ga2O3 by controllable introduction of the lattice disorder with ion irradiation and monitoring its evolution as a function of ion dose, flux, and temperature. Already the dose dependence acquired at room temperature suggested prominently high mobility of intrinsic defects in α-Ga2O3, since we observed two distinct disordered regions—near the surface and in the bulk—instead of a Gaussian shape following the ballistic defects production process. Moreover, the disorder accumulation has shown to be highly sensitive to the variation of the ion flux and temperature, known in the literature as the dose-rate effect. Therefore, by monitoring the process as a function of the flux and temperature, we observed such dose-rate effect in α-Ga2O3 with an activation energy of 0.33 ± 0.04 eV, which we attributed to the migration barrier of the intrinsic defects in the Ga sublattice, from where we collected the experimental data. By setting these results in the context of the theoretical data available in the literature, we argued that this energy may be attributed to the migration activation of the Ga self-interstitials in α-Ga2O3.

• Azarov, Alexander; García Fernández, Javier; Zhao, Junlei; Djurabekova, Flyura; He, Huan & He, Ru [Vis alle 13 forfattere av denne artikkelen] (2023). Universal radiation tolerant semiconductor. Nature Communications. ISSN 2041-1723. 14, s. 1–8. doi: 10.1038/s41467-023-40588-0. Fulltekst i vitenarkiv
• Polyakov, Alexander Y.; Yakimov, Eugene B.; Nikolaev, Vladimir I.; Pechnikov, Alexei I.; Miakonkikh, Andrej V. & Azarov, Alexander [Vis alle 12 forfattere av denne artikkelen] (2023). Impact of Hydrogen Plasma on Electrical Properties and Deep Trap Spectra in Ga2O3 Polymorphs. Crystals. ISSN 2073-4352. 13(9), s. 1–25. doi: 10.3390/cryst13091400. Fulltekst i vitenarkiv Vis sammendrag

  In this study, the results of hydrogen plasma treatments of β-Ga2O3, α-Ga2O3, κ-Ga2O3 and γ-Ga2O3 polymorphs are analyzed. For all polymorphs, the results strongly suggest an interplay between donor-like hydrogen configurations and acceptor complexes formed by hydrogen with gallium vacancies. A strong anisotropy of hydrogen plasma effects in the most thermodynamically stable β-Ga2O3 are explained by its low-symmetry monoclinic crystal structure. For the metastable, α-, κ- and γ-polymorphs, it is shown that the net result of hydrogenation is often a strong increase in the density of centers supplying electrons in the near-surface regions. These centers are responsible for prominent, persistent photocapacitance and photocurrent effects.

• Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Karaseov, Platon; Titov, Andrei; Karabeshkin, Konstantin & Struchkov, Andrei [Vis alle 7 forfattere av denne artikkelen] (2022). Interplay of the disorder and strain in gallium oxide. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-19191-8. Fulltekst i vitenarkiv

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• Azarov, Alexander; Park, Ji-Hyeon; Jeon, Dae-Woo; Monakhov, Eduard & Kuznetsov, Andrej (2023). Defect migration energies in Ga2O3 polymorphs measured by variations of temperature and flux under irradiation.
• Azarov, Alexander (2023). Radiation disorder induced ordering.
• Azarov, Alexander; Bazioti, Kalliopi; Venkatachalapathy, Vishnukanthan; Vajeeston, Ponniah; Monakhov, Eduard & Kuznetsov, Andrej (2022). Ion-beam-induced phase transitions in gallium oxide: impact of the implantation temperature .
• Azarov, Alexander; Bazioti, Kalliopi; Venkatachalapathy, Vishnukanthan; Vajeeston, Ponniah; Monakhov, Eduard & Kuznetsov, Andrej (2022). Disorder-induced ordering in Ga2O3 polymorphs.

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