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It has recently been demonstrated that electron beam injection into p-type β-gallium oxide leads to a significant linear increase in minority carrier diffusion length with injection duration, followed by its saturation. The effect was ascribed to trapping of non-equilibrium electrons (generated by a primary electron beam) at meta-stable native defect levels in the material, which in turn blocks recombination through these levels. In this work, in contrast to previous studies, the effect of electron injection in p-type Ga2O3 was investigated using cathodoluminescence technique in situ in scanning electron microscope, thus providing insight into minority carrier lifetime behavior under electron beam irradiation. The activation energy of ∼0.3 eV, obtained for the phenomenon of interest, is consistent with the involvement of Ga vacancy-related defects.
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Electron beam irradiation-induced transport and recombination in p-type gallium oxide grown on (001) β -Ga2O3 substrate
This study investigates minority electron diffusion length and carrier recombination phenomena in p-type 300 nm-thick Ga2O3 films homoepitaxially grown over a (001) tin-doped β-Ga2O3 conductive substrate. This research is novel due to its systematic and near-simultaneous measurements in the top layer of a p-Ga2O3/n-Ga2O3 structure using independent electron beam-induced current and cathodoluminescence techniques. Previous work primarily focused on heteroepitaxial architectures or gallium oxide grown over insulating substrates of the same material. In this work, the activation energies related to point defects in gallium oxide were extracted from temperature-dependent incremental electron beam irradiation experiments to gain insight into the defect landscape and its influence on minority carrier transport and recombination dynamics.
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- Award ID(s):
- 2341747
- PAR ID:
- 10668016
- Publisher / Repository:
- AIP
- Date Published:
- Journal Name:
- Journal of Applied Physics
- Volume:
- 138
- Issue:
- 7
- ISSN:
- 0021-8979
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Minority carrier diffusion length in undoped p-type gallium oxide was measured at various temperatures as a function of electron beam charge injection by electron beam-induced current technique in situ using a scanning electron microscope. The results demonstrate that charge injection into p-type β-gallium oxide leads to a significant linear increase in minority carrier diffusion length followed by its saturation. The effect was ascribed to trapping of non-equilibrium electrons (generated by a primary electron beam) on metastable native defect levels in the material, which in turn blocks recombination through these levels. While previous studies of the same material were focused on probing a non-equilibrium carrier recombination by purely optical means (cathodoluminescence), in this work, the impact of charge injection on minority carrier diffusion was investigated. The activation energy of ∼0.072 eV, obtained for the phenomenon of interest, is consistent with the involvement of Ga vacancy-related defects.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1063/5.0288118
