Application of the nonuniform-field treatment to the infrared properties of LiF

1969 ◽  
Vol 47 (1) ◽  
pp. 51-64 ◽  
Author(s):  
A. J. Beaulieu
Keyword(s):  
Thin Films ◽  
Optical Phonon ◽  
Phonon Frequency ◽  
Quantitative Agreement ◽  
Longitudinal Optical ◽  
Optical Frequency ◽  
Nonuniform Field ◽  
Optical Phonon Frequency ◽  
Experimental Values ◽  
Comparison Of The Results

The "nonuniform-field treatment" developed earlier for infinitely thick crystals is applied to the LiF crystal. Comparison with experimental results both at 45° and at small angles of incidence gives good quantitative agreement only when the ratio of the longitudinal optical frequency to the transverse optical frequency is assumed to be 1.7 instead of 2.2 as predicted by the Lyddane–Sach–Teller relation. An extension of the treatment to thin films is presented and the comparison of the results with Berreman's experimental values indicates that the asymmetry and the amplitude of the features which could not be explained before can be predicted in terms of the nonuniform-field treatment, again provided the optical phonon frequency ratio is 1.7.

scholarly journals Micro-Raman Mapping of the Strain Field in GaAsN/GaAsN:H Planar Heterostructures: A Brief Review and Recent Evolution

2019 ◽  
Vol 9 (22) ◽  
pp. 4864
Author(s):  
Giulotto ◽  
Geddo
Keyword(s):  
Strain Field ◽  
Strain State ◽  
Phonon Frequency ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Strain Behavior ◽  
Irradiation Intensity ◽  
Specific Geometry ◽  
Optical Phonon Frequency ◽  
Low Levels

Raman scattering is an effective tool for the investigation of the strain state of crystalline solids. In this brief review, we show how the analysis of the GaAs-like longitudinal optical phonon frequency allowed to map the strain behavior across interfaces in planar heterostructures consisting of GaAsN wires embedded in GaAsN:H matrices. Moreover, we recently showed how the evolution of the longitudinal optical frequency with increasing H dose strongly depends on polarization geometry. In a specific geometry, we observed a relaxation of the GaAs selection rules. We also present new results which demonstrate how laser irradiation intensity–even at low levels–may affect the line shape of the GaAs-like spectral features in GaAsN hydrogenated materials.

Strain-Induced Shift of Optical Phonon Frequency in InGaP Layers Grown on GaAs Substrates

1987 ◽  
Vol 26 (Part 2, No. 10) ◽  
pp. L1597-L1600 ◽  
Author(s):  
Takamasa Kato ◽  
Takashi Matsumoto ◽  
Mitsuru Hosoki ◽  
Tetsuro Ishida
Keyword(s):  
Optical Phonon ◽  
Phonon Frequency ◽  
Gaas Substrates ◽  
Optical Phonon Frequency

Raman scattering on silicon nanowires: The thermal conductivity of the environment determines the optical phonon frequency

2006 ◽  
Vol 88 (23) ◽  
pp. 233114 ◽  
Author(s):  
H. Scheel ◽  
S. Reich ◽  
A. C. Ferrari ◽  
M. Cantoro ◽  
A. Colli ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raman Scattering ◽  
Silicon Nanowires ◽  
Optical Phonon ◽  
Phonon Frequency ◽  
Optical Phonon Frequency

Porosity-Induced Optical Phonon Engineering in III-V Compounds

1998 ◽  
Vol 536 ◽  
Author(s):  
I. M. Tiginyanu ◽  
G. Irmer ◽  
J. Monecke ◽  
H. L. Hartnagel ◽  
A. Vogt ◽  
...  
Keyword(s):  
Optical Phonon ◽  
Phonon Frequency ◽  
Vibrational Mode ◽  
Longitudinal Optical ◽  
Electrochemical Anodization ◽  
Raman Analysis ◽  
Porous Layers ◽  
Surface Phonon ◽  
Promising Tool ◽  
Phonon Spectra

AbstractNew possibilities for modifying the phonon spectra of III-V compounds are evidenced by micro-Raman analysis of porous layers prepared by electrochemical anodization of (111 )Aoriented n-GaP substrates. In particular, a surface-related vibrational mode along with a porosity-induced decoupling between the longitudinal optical (LO) phonon and plasmon are observed. We prove that filling in the pores with other materials (aniline as a first approach) is a promising tool for controlling the surface phonon frequency.

The electrostatic coupling of longitudinal optical phonon and plasmon in wurtzite InN thin films

2010 ◽  
Vol 96 (4) ◽  
pp. 041908 ◽  
Author(s):  
Y.-M. Chang ◽  
S. C. Liou ◽  
C. H. Chen ◽  
H.-M. Lee ◽  
S. Gwo
Keyword(s):  
Thin Films ◽  
Optical Phonon ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Electrostatic Coupling

Electron–Interface–Phonon Interaction and Magnetopolaronic Impurity Transitions in Quantum Wells

1997 ◽  
Vol 11 (08) ◽  
pp. 991-1008 ◽  
Author(s):  
R. Chen ◽  
D. L. Lin
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Phonon Frequency ◽  
Transition Energy ◽  
Bulk Sample ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Phonon Interaction ◽  
Double Heterostructure

The polaronic effect on the hydrogenic 1s–2p+ transition energy of a donor impurity located at the quantum well center in a double heterostructure is studied theoretically in detail. The electron–optical–phonon interaction Hamiltonian is derived on the basis of eigenmodes of lattice vibrations supported by the double heterostructure. Both the confined and interface phonon modes are included in the electron–phonon coupling. The transition energy is calculated as a function of the applied magnetic field for GaAs/Al 1-x Ga x As samples of well -widths d=125 Å, 210 Å and 450 Å by the second-order perturbation. Wide transition gaps are predicted around the two-level and three-level resonances for all three cases. It is found that the transition gap narrows with the increasing well-width but remains larger than the LO and TO phonon frequency difference for d=450 Å as is observed. We also perform the same calculation by assuming that the confined electron interacts with three-dimensional and two-dimensional phonon modes. The transition energy spectra from these calculations appear to be similar to those for a bulk sample, the spectrum splits at the resonance with the longitudinal optical phonon frequency only. From comparisons of our results with these calculations as well as with experiments, it is conclusively established that the wide gap of transition energy is solely due to the interface modes.

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