High-Pressure Raman Scattering of Biaxially Strained GaN on GaAs

1997 ◽  
Vol 468 ◽  
Author(s):  
H. Siegle ◽  
A. R. Goñi ◽  
C. Thomsen ◽  
C. Ulrich ◽  
K. Syassen ◽  
...  
Keyword(s):  
High Pressure ◽  
Raman Scattering ◽  
Epitaxial Layer ◽  
Gaas Substrate ◽  
Biaxial Strain ◽  
Phonon Modes ◽  
Bulk Gaas ◽  
Grüneisen Parameters ◽  
Bulk Gan ◽  
Gruneisen Parameters

ABSTRACTWe present results of high-pressure Raman-scattering experiments on bulk GaN and GaN grown on GaAs. We determined the Grüneisen parameters of both the cubic TO and LO phonon modes and the hexagonal A1, E1 and E2 modes. Our measurements reveal that the Grüneisen parameters for the GaAs substrate are about 30% smaller than those of bulk GaAs. This is a consequence of the lower compressibility of GaN compared to GaAs, which results in a pressure-induced biaxial strain on the substrate. From the pressure behavior of the GaAs modes and by comparing with our results for bulk GaN we obtained information about the biaxial strain in the GaN epitaxial layer.

Grüneisen parameters for silicon clathrates determined by Raman scattering

1999 ◽  
Vol 60 (21) ◽  
pp. 14507-14509 ◽  
Author(s):  
Y. Guyot ◽  
L. Grosvalet ◽  
B. Champagnon ◽  
E. Reny ◽  
C. Cros ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Silicon Clathrates ◽  
Grüneisen Parameters ◽  
Gruneisen Parameters

Micro-Raman Scattering Study of Strain Fields in Homo-Epitaxial Layer on Nitrogen-Doped 4H-SiC Substrate

2017 ◽  
Vol 897 ◽  
pp. 283-286
Author(s):  
Daisuke Fukunaga ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Shinya Sato ◽  
Hiroshi Tsuge ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Epitaxial Layer ◽  
Tensile Strain ◽  
Nitrogen Concentration ◽  
Phonon Modes ◽  
Cross Sectional ◽  
Strain Fields ◽  
Nitrogen Doped ◽  
Substrate Interface ◽  
Scattering Study

The strain fields in a 4H-SiC homo-epitaxial layer deposited on a nitrogen-doped 4H-SiC substrate were studied using Raman scattering microscopy. The cross-sectional (1-100) and (11-20) surfaces of the epitaxial substrate were examined through the peak shifts of several Raman-active phonon modes for 4H-SiC, and tensile strain was found along the direction of 4° off the c-axis at the epilayer/substrate interface. The effect of the facet trace in the substrate, which has a higher nitrogen concentration than the other parts of the substrate, was also studied. The tensile strain at the epilayer/substrate interface was found to be hardly enhanced for the epilayer deposited on the facet trace.

scholarly journals Phase Transitions in Natural Vanadinite at High Pressures

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1217
Author(s):  
Yingxin Liu ◽  
Liyun Dai ◽  
Xiaojing Lai ◽  
Feng Zhu ◽  
Dongzhou Zhang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Changes ◽  
High Pressures ◽  
Color Change ◽  
X Ray Diffraction ◽  
Grüneisen Parameters ◽  
Reversible Phase Transition ◽  
Diamond Anvil ◽  
Gruneisen Parameters

The structural stability of vanadinite, Pb5[VO4]3Cl, is reported by high-pressure experiments using synchrotron radiation X-ray diffraction (XRD) and Raman spectroscopy. XRD experiments were performed up to 44.6 GPa and 700 K using an externally-heated diamond anvil cell (EHDAC), and Raman spectroscopy measurements were performed up to 26.8 GPa at room temperature. XRD experiments revealed a reversible phase transition of vanadinite at 23 GPa and 600 K, which is accompanied by a discontinuous volume reduction and color change of the mineral from transparent to reddish during compression. The high-pressure Raman spectra of vanadinite show apparent changes between 18.0 and 22.8 GPa and finally become amorphous at 26.8 GPa, suggesting structural transitions of this mineral upon compression. The structural changes can be distinguished by the emergence of a new vibrational mode that can be attributed to the distortion of [VO4] and the larger distortion of the V–O bonds, respectively. The [VO4] internal modes in vanadinite give isothermal mode Grüneisen parameters varying from 0.149 to 0.286, yielding an average VO4 internal mode Grüneisen parameters of 0.202.

Photoluminescence and Raman Scattering from (CdSe)m,(ZnSe)n-ZnSe Multiple Quantum Wells Under Hydrostatic Pressure

1995 ◽  
Vol 406 ◽  
Author(s):  
J. Q. Zhang ◽  
Z. X. Liu ◽  
Z. P. Wang ◽  
H. X. Han ◽  
G. H. Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Quantum Well ◽  
Raman Scattering ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Phonon Modes ◽  
Quantum Well Structure

AbstractThe photoluminescence and Raman scattering of {|(CdSe)1 (ZnSe)3|14-(ZnSe)130} × 5 multiple quantum well structure have been investigated at 77 K and under hydrostatic pressure up to 7 GPa. Resonant excitations have been accomplished by turning the electronic levels under hydrostatic high pressure. Two kind of excitons and ZnSe-like LO phonon modes as well as their pressure behavior are presented.

Structural stability and Raman scattering of InN nanowires under high pressure

2010 ◽  
Vol 25 (12) ◽  
pp. 2330-2335 ◽  
Author(s):  
L.D. Yao ◽  
S.D. Luo ◽  
X. Shen ◽  
S.J. You ◽  
L.X. Yang ◽  
...  
Keyword(s):  
High Pressure ◽  
Raman Scattering ◽  
Structural Transition ◽  
Relative Volume ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Equation Of States ◽  
Diamond Anvil ◽  
Murnaghan Equation

High-pressure in situ angular dispersive x-ray diffraction study on the wurtzite-type InN nanowires has been carried out by means of the image-plate technique and diamond-anvil cell (DAC) up to about 31.8 GPa. The pressure-induced structural transition from the wurtzite to a rocksalt-type phase occurs at about 14.6 GPa, which is slightly higher than the transition pressure of InN bulk materials (∼12.1 GPa). The relative volume reduction at the transition point is close to 17.88%, and the bulk modulus B0 is determined through fitting the relative volume-pressure experimental data related to the wurtzite and rocksalt phases to the Birch–Murnaghan equation of states. Moreover, high-pressure Raman scattering for InN nanowires were also investigated in DAC at room temperature. The corresponding structural transition was confirmed by assignment of phonon modes. We calculated the mode Grüneisen parameters for the wurtzite and rocksalt phases of InN nanowires.

Cristal-growth dynamics of n-doped gaAs

1992 ◽  
Vol 50 (2) ◽  
pp. 1544-1545
Author(s):  
Pham V. Huong ◽  
Stéphanie Bouchet ◽  
Jean-Claude Launay
Keyword(s):  
Crystal Growth ◽  
Spatial Resolution ◽  
Epitaxial Layer ◽  
Outer Surface ◽  
Gaas Substrate ◽  
Structural Modification ◽  
Growth Dynamics ◽  
Argon Laser ◽  
High Anisotropy ◽  
Crystal Gaas

Microstructure of epitaxial layers of doped GaAs and its crystal growth dynamics on single crystal GaAs substrate were studied by Raman microspectroscopy with a Dilor OMARS instrument equipped with a 1024 photodiode multichannel detector and a ion-argon laser Spectra-Physics emitting at 514.5 nm.The spatial resolution of this technique, less than 1 μm2, allows the recording of Raman spectra at several spots in function of thickness, from the substrate to the outer deposit, including areas around the interface (Fig.l).The high anisotropy of the LO and TO Raman bands is indicative of the orientation of the epitaxial layer as well as of the structural modification in the deposit and in the substrate at the interface.With Sn doped, the epitaxial layer also presents plasmon in Raman scattering. This fact is already very well known, but we additionally observed that its frequency increases with the thickness of the deposit. For a sample with electron density 1020 cm-3, the plasmon L+ appears at 930 and 790 cm-1 near the outer surface.

scholarly journals Atomic-layered MoS2 on SiO2 under high pressure: Bimodal adhesion and biaxial strain effects

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
R. S. Alencar ◽  
K. D. A. Saboia ◽  
D. Machon ◽  
G. Montagnac ◽  
V. Meunier ◽  
...  
Keyword(s):  
High Pressure ◽  
Biaxial Strain ◽  
Strain Effects ◽  
Layered Mos2

Gruneisen parameters of bead-spring chains: MD simulation and theory

2020 ◽  
Vol 153 (24) ◽  
pp. 244903
Author(s):  
Craig S. Stevenson ◽  
John G. Curro ◽  
John D. McCoy
Keyword(s):  
Md Simulation ◽  
Grüneisen Parameters ◽  
Gruneisen Parameters

scholarly journals Resonance and antiresonance in Raman scattering in GaSe and InSe crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Osiekowicz ◽  
D. Staszczuk ◽  
K. Olkowska-Pucko ◽  
Ł. Kipczak ◽  
M. Grzeszczyk ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Temperature Effect ◽  
Band Gap ◽  
Raman Spectra ◽  
Quantum Interference ◽  
Optical Band Gap ◽  
Phonon Coupling ◽  
Phonon Modes ◽  
Electron Phonon Coupling ◽  
Resonant Raman

AbstractThe temperature effect on the Raman scattering efficiency is investigated in $$\varepsilon$$ ε -GaSe and $$\gamma$$ γ -InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.

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