Emission properties of Ga2O3nano-flakes: effect of excitation density.
In the quest of developing high performance electronic and optical devices and more cost effective fabrication processes of monoclinic β-Ga2O3, new growth techniques and fundamental electronic and optical properties of defects have to be explored. By heating of dissolved metallic Ga in HCl in a NH3and N2atmosphere, nano-flake films of monoclinic β-phase Ga2O3were grown as confirmed by XRD. From optical measurements, we observe two strong emissions. A red band peaking at ~2.0 eV and a UV band at ~3.8 eV. The band at ~2.0 eV is attributed to donor-acceptor pair recombination where the donor and acceptor level is suggested to be related to VOand nitrogen, respectively. By studying the dependence of the intensity of the UV band at 3.8 eV versus excitation density, a model is suggested. In the model, it is assumed that local potential fluctuations forming minima (maxima), where the carriers would be localized with a summarized band offset for conduction and valence band of 1 eV. The origin of the fluctuations is tentatively suggested to be related to micro-inclusions of different phases in the film.
Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden.
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Pozina
Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden.
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Forsberg
St-Petersburg Academic University Khlopina 8/3, 194021, St-Petersburg, Russia.|ITMO University, Kronverkskiy pr. 49, 197101 St. Petersburg, Russia.
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Kaliteevski
Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden.
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Hemmingsson