Title: Infrared reflectance and transmission spectra of II-IV-V2 semiconducting compounds: CdGeAs2
Abstract: The infrared reflectance and transmission spectra of polycrystalline and amorphous CdGeAs2 were measured at room temperature in the 6000-50 cm−1 region. Shifting of both the absorption edge and the two-phonon absorption to higher wavenumbers at the crystalline-glass transition was discussed on the basis of viewing the amorphous phase as a disturbance of the crystalline structure. The optical constants were calculated from the far-IR reflectance spectra, using Kramers-Kronig analysis. The calculated damping parameters were higher for the amorphous state than for the crystalline state, indicating the lattice disorder of the amorphous state. The results for polycrystalline CdGeAs2 were consistent with those observed earlier with single crystals. The qualitative and quantitative parameters for the bond ionicity were estimated, indicating that the chemical bonds in CdGeAs2 possessed a large covalent component. Band assignments were made for the spectra of CdGeAs2 phases on the basis of related band assignments for CdSiAs2, CdAs2, and GaAs. The wavenumber differences for the compared bands were due mainly to mass differences for related substituted atoms in the compared materials.
Publication Year: 1990
Publication Date: 1990-01-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 13
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