Far-infrared absorption in CdTe

1977 ◽  
Vol 55 (22) ◽  
pp. 2013-2018 ◽  
Author(s):  
E. Batalla ◽  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Absorption Spectrum ◽  
Brillouin Zone ◽  
Infrared Absorption ◽  
Far Infrared ◽  
High Accuracy ◽  
Compound Semiconductor ◽  
Model Parameters ◽  
Fourier Transform Spectrometer ◽  
Phonon Density ◽  
Phonon Density Of States

Far-infrared absorption in the II–VI compound semiconductor Cd Te has been measured using a Fourier transform spectrometer. Two-phonon density-of-states curves were calculated from shell model parameters determined by Rowe, Nicklow, Price, and Zanio and were compared to the high-accuracy absorption spectrum. Two-phonon combinations and the location of the corresponding critical points in the Brillouin zone were identified with features in the absorption spectrum. From these assignments, accurate values of some normal mode frequencies at certain points in the Brillouin zone were determined.

scholarly journals Far-infrared absorption in cubic ZnS

1976 ◽  
Vol 54 (10) ◽  
pp. 1053-1060 ◽  
Author(s):  
E. A. Kwasniewski ◽  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Absorption Spectrum ◽  
Infrared Absorption ◽  
Phonon Dispersion ◽  
Far Infrared ◽  
Fourier Transform Spectrometer ◽  
High Symmetry ◽  
Phonon Density ◽  
Zone Boundary ◽  
Phonon Density Of States ◽  
Phonon Dispersion Curves

Far-infrared absorption in cubic ZnS due to single-phonon and two-phonon processes was measured with a high resolution, far-infrared Fourier transform spectrometer. A 14-parameter lattice dynamical shell model was fitted to phonon dispersion curves measured by Vagelatos et al. The two-phonon density-of-states calculated with these parameters was compared with the absorption spectrum. Two-phonon combinations and their locations in the Brillouin zone were identified with features of the absorption spectrum. Critical points were found on or near the zone boundary and not only at high symmetry points as suggested previously.

A MODEL FOR OPTICAL ABSORPTION OF AMORPHOUS GaAs IN THE FAR-INFRARED RANGE BY USING AN OPERATIONAL TECHNIQUE

1999 ◽  
Vol 13 (25) ◽  
pp. 919-923 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
Optical Absorption ◽  
Absorption Coefficient ◽  
Far Infrared ◽  
Structural Disorder ◽  
Optical Absorption Coefficient ◽  
Infrared Range ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Operational Technique ◽  
Dynamical Disorder

By considering a sample of amorphous GaAs with a small zone of dynamical disorder, an expression for the optical absorption coefficient and phonon density of states in the low region of the far-infrared range is obtained. To get to this end, absorption corresponding to structural disorder is neglected.

Two-phonon absorption in InSb, InAs, and GaAs

1976 ◽  
Vol 54 (16) ◽  
pp. 1676-1682 ◽  
Author(s):  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Far Infrared ◽  
Inelastic Neutron ◽  
Model Fit ◽  
Fourier Transform Spectrometer ◽  
Phonon Density ◽  
Phonon Dispersion Curves ◽  
Phonon Absorption ◽  
Good Agreement

Far-infrared absorption in the III–V compound semiconductors InSb, InAs, and GaAs has been measured using a Fourier transform spectrometer. The high-resolution spectra of the three materials were found to be very similar. Features on the spectra were assigned to two-phonon sum and difference processes with the aid of two-phonon density-of-states curves for InSb and GaAs calculated from a shell model fit to phonon dispersion curves. Interpretation of the spectrum of InAs was possible because of its similarity to that of InSb and GaAs. The frequencies of phonons at certain points in the Brillouin zone of InSb and GaAs determined from the mode assignments to the infrared spectra were in good agreement with previous measurements by inelastic neutron scattering and Raman scattering.

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