Amorphous gallium oxide sulfide: A highly mismatched alloy
| Autor: | Oscar D. Dubon, Wladek Walukiewicz, Petra Specht, M. Jaquez, Kin Man Yu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
chemistry.chemical_classification Materials science Sulfide Band gap Alloy Analytical chemistry General Physics and Astronomy chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Sulfur Amorphous solid chemistry 0103 physical sciences engineering 0210 nano-technology Absorption (electromagnetic radiation) Stoichiometry Deposition (law) |
| Zdroj: | Journal of Applied Physics. 126:105708 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.5111985 |
| Popis: | Stoichiometric gallium oxide sulfide Ga2(O1 − xSx)3 thin-film alloys were synthesized by pulsed-laser deposition with x ≤ 0.35. All deposited Ga2(O1 − xSx)3 films were found to be amorphous. Despite the amorphous structure, the films have a well-defined, room-temperature optical bandgap tunable from 5.0 eV down to 3.0 eV. The optical absorption data are interpreted using a modified valence-band anticrossing model that is applicable for highly mismatched alloys. The model provides a quantitative method to more accurately determine the bandgap as well as an insight into how the band edges are changing with composition. The observed large reduction in energy bandgap with a small sulfur ratio arises from the anticrossing interaction between the valence band of Ga2O3 and the localized sulfur level at 1.0 eV above the Ga2O3 valence-band maximum. |
| Databáze: | OpenAIRE |
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