We present a model for exciton-mediated first-order Raman
scattering by longitudinal optical phonons in the presence of surfaces and point
defects. It is consistent with the experimental data for all wurtzite structure
materials investigated and reviewed here (GaN, InN, ZnO and CdS) and also
explains not yet understood observations in the literature. We distinguish
between the involvement of elastic scattering by the surface and by point defects
in the scattering process. Surface scattering causes the dependence of the line
position on the crystal orientation of the excited surface in pure crystals. Point
defect scattering is independent of the crystal orientation and appears as an
additional contribution in defect-rich crystals. We postulate the polarization
properties of these distinct processes which are in good agreement with the
experiments and allow us to identify and separate the contributions of these two
effects from the polarized spectra.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:80302 |
| Date | 02 August 2022 |
| Creators | Kranert, Christian, Schmidt-Grund, Rüdiger, Grundmann, Marius |
| Publisher | IOP Publishing |
| 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 | 113048 |
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