We determined the dielectric function of the alloy system (InxGa1−x)2O3 by spectroscopic
ellipsometry in the wide spectral range from 0.5 eV to 8.5 eV and for In contents ranging from
x = 0.02 to x = 0.61. The predicted optical transitions for binary, monoclinic β-Ga2O3, and cubic
bcc-In2O3 are well reflected by the change of the dielectric functions’ lineshape as a function of the
In content. In an intermediate composition range with phase-separated material (x ≈ 0.3…0.4), the
lineshape differs considerably, which we assign to the presence of the high-pressure rhombohedral
InGaO3-II phase, which we also observe in Raman experiments in this range. By model analysis of
the dielectric function, we derived spectra of the refractive index and the absorption coefficient and
energy parameters of electronic band-band transitions. We discuss the sub-band gap absorption tail
in relation to the influence of the In 4d orbitals on the valence bands. The data presented here provide
a basis for a deeper understanding of the electronic properties of this technologically important
material system and may be useful for device engineering.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:31191 |
| Date | 09 August 2018 |
| Creators | Schmidt-Grund, Rüdiger, Kranert, Christian, Böntgen, Tammo, von Wenckstern, Holger, Krauß, Hannes, Grundmann, Marius |
| Publisher | American Institute of Physics, Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 0021-8979, 1089-7550, 053510 |
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