Intensity of theRRlongitudinal optical phonon branch for Raman scattering by solid HD

1989 ◽  
Vol 40 (14) ◽  
pp. 9863-9867 ◽  
Author(s):  
M. Ali ◽  
R. H. Tipping ◽  
J. D. Poll
Keyword(s):  
Raman Scattering ◽  
Optical Phonon ◽  
Phonon Branch ◽  
Solid Hd ◽  
Optical Phonon Branch

EFFECT OF MULTIPLE PHONON BRANCHES ON THE PHASE TRANSITIONAL BEHAVIOR OF A TWO-DIMENSIONAL POLARON GAS

1995 ◽  
Vol 09 (07) ◽  
pp. 849-857
Author(s):  
SOMA MUKHOPADHYAY ◽  
ASHOK CHATTERJEE
Keyword(s):  
Variational Method ◽  
Optical Phonon ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Two Dimensional ◽  
Phase Approximation ◽  
Phonon Branch ◽  
Transitional Behavior ◽  
Additional Branch ◽  
Optical Phonon Branch

Using an all-coupling variational method and the random phase approximation, it is shown that a two-dimensional polaron gas exhibiting no localization-delocalization transition with a single optical phonon branch may undergo such a transition in the presence of an additional phonon branch. However, if the system already shows a transition, with a single phonon branch, then the effect of an additional branch is just to enhance the low-mobility self-trapped phase of the polaron.

Raman scattering spectra in C-implanted GaN epilayers

2001 ◽  
Vol 680 ◽  
Author(s):  
W. H. Sun ◽  
S. J. Chua ◽  
J. Zhang ◽  
L. S. Wang ◽  
M. S. Hao ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Annealing Temperature ◽  
Phonon Scattering ◽  
Phonon Dispersion ◽  
Phonon Branch ◽  
Phonon Dispersion Curves ◽  
Scattering Spectra ◽  
Raman Scattering Spectra ◽  
Post Implantation ◽  
Optical Phonon Branch

ABSTRACTWe have investigated the Raman scattering spectra in C-implanted GaN epilayers. (a) In as-implanted GaN, new Raman bands at 293, 376, 669, 1027, 1094 and 1053 cm−1 appeared. From phonon-dispersion curves for hexagonal GaN, the 293 cm−1 and 669 cm−1 bands were tentatively assigned to the highest acoustic-phonon branch and the optical-phonon branch at the Brillouin zone boundaries, respectively; the 1027 and 1094 cm−1 peaks might be caused by two-phonon scattering involving the 376 and 669 cm−1 phonons, and the 376 cm−1and A1(LO) phonons respectively. (b) Two sharp bands at ∼1350 and ∼1600 cm−1 were observed in the Raman spectra of carbon- implanted GaN after post-implantation annealing treatments. The intensities of these two bands increased while their full widths at half maximum decreased with increasing annealing temperature. We assigned them, respectively, to the D and G bands of small graphite crystallites arising from C implantation and post-implantation annealing. The observation of these two bands indicates the formation of small graphite crystallites in C-implanted GaN.

Study of anharmonicity in pure and doped InSe by Raman scattering

2018 ◽  
Vol 32 (30) ◽  
pp. 1850340 ◽  
Author(s):  
Mahmoud Zolfaghari
Keyword(s):  
Raman Scattering ◽  
Temperature Dependence ◽  
Temperature Variation ◽  
Optical Phonon ◽  
Line Center ◽  
Anharmonic Effect ◽  
Layered Semiconductor ◽  
Center Shift ◽  
Raman Modes ◽  
Quartic Anharmonicity

With the help of temperature dependence, Raman scattering anharmonic effect of various modes of layered semiconductor InSe over temperature range of 20–650 K has been studied. It was found that with an increase in temperature, anharmonicity will increase. Two and three phonons coupling with optical phonon, are used to describe temperature-induced anharmonicity in the linewidth of Raman modes. It was found that the temperature variation of the phonon parameter can be accounted for well by the cubic term in anharmonic model. To describe line-center shift of Raman modes, a model not considering independently cubic and quartic anharmonicity was used. A similar study has been done for InSe doped with different concentration of GaS dopant. The result of temperature study of InSe doped with GaS revealed that in this case anharmonicity increases with an increase in dopant and an increase in temperature.

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

Raman scattering study of the long-wavelength longitudinal-optical-phonon–plasmon coupled modes in high-mobility InN layers

2009 ◽  
Vol 79 (15) ◽  
Author(s):  
Ramon Cuscó ◽  
Jordi Ibáñez ◽  
Esther Alarcón-Lladó ◽  
Luis Artús ◽  
Tomohiro Yamaguchi ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Optical Phonon ◽  
High Mobility ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Coupled Modes ◽  
Long Wavelength ◽  
Scattering Study

Raman Study of Strain and Confinement Effects in Si/Ge Strained Layer Superlattices Under Hydrostatic Pressure

1991 ◽  
Vol 220 ◽  
Author(s):  
Zhifeng Sui ◽  
Irving P. Herman ◽  
Joze Bevk
Keyword(s):  
Hydrostatic Pressure ◽  
Raman Scattering ◽  
Optical Phonon ◽  
Phonon Frequency ◽  
Optical Phonons ◽  
Biaxial Strain ◽  
Strained Layer ◽  
Strained Layer Superlattice ◽  
Raman Study ◽  
Strained Layer Superlattices

ABSTRACTThe effects of strain and confinement on optical phonons in a Si12Ge4 strained layer superlattice grown by MBE on c-Si (001) were studied as a function of hydrostatic pressure (T = 295 K) using Raman scattering. The change of phonon frequency with pressure, dω/dP, for the principal quasi-confined LO mode in the Ge layers is found to be significantly smaller than that for bulk crystalline Ge because the magnitude of biaxial strain decreases in the Ge layers with added pressure and because the Grüneisen parameter of the confined mode is smaller than that of the Γ-point optical phonon. More generally, it is noted that the magnitude of biaxial strain in many strained layer superlattices initially decreases with the application of hydrostatic pressure, making the structures more stable.

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