scholarly journals Surface- and point-defect-related Raman scattering in wurtzite semiconductors excited above the band gap

2013 ◽  
Vol 15 (11) ◽  
pp. 113048 ◽  
Author(s):  
C Kranert ◽  
R Schmidt-Grund ◽  
M Grundmann
Keyword(s):  
Raman Scattering ◽  
Point Defect ◽  
Band Gap ◽  
Wurtzite Semiconductors

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.

scholarly journals Unusual Formation of Point-Defect Complexes in the Ultrawide-Band-Gap Semiconductor β−Ga2O3

2019 ◽  
Vol 9 (4) ◽  
Author(s):  
Jared M. Johnson ◽  
Zhen Chen ◽  
Joel B. Varley ◽  
Christine M. Jackson ◽  
Esmat Farzana ◽  
...  
Keyword(s):  
Point Defect ◽  
Band Gap ◽  
Defect Complexes ◽  
Unusual Formation

Profiling Composition Variations in Composition-Modulated GaP/InP Short-Period Superlattices Using Resonance Raman Scattering

1999 ◽  
Vol 583 ◽  
Author(s):  
H. M. Cheong ◽  
Yong Zhang ◽  
A. G. Norman ◽  
J. D. Perkins ◽  
A. Mascarenhas ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Band Gap ◽  
Resonance Raman ◽  
Band Gap Energy ◽  
Resonance Raman Scattering ◽  
Rich Region ◽  
Gap Energy ◽  
Composition Modulation ◽  
Short Period ◽  
Short Period Superlattices

AbstractWe use resonance Raman scattering (RRS) and electroreflection (ER) measurements to profile the the composition and strain variations in laterally composition-modulated (CM) GaP/InP short-period superlattices (SPS's). The ER spectra of a GaP2.2/InP2.0 SPS give the fundamental band-gap energy at 1.69±0.05eV, which is about 210 meV lower than the band gap energy of a GaInP random alloy with the same overall composition. The RRS measurements reveal strong dependences of the phonon spectrum on the polarization and the excitation energy. In RRS spectra measured with the polarization of both excitation and scattered photons along the composition modulation direction, the GaP-like longitudinal optical (LO) phonon redshifts by 4.0±0.5 cm−1 near the resonance with the fundamental energy gap. On the other hand, when the polarizations are orthogonal to the composition modulation, the LO phonons redshift as much as 16 cm−1 at low excitation energies. A comparison of the experimental data with a model calculation gives the average In composition in the In-rich region as 0.70±0.02, and the average Ga composition in the Ga-rich region as 0.68±0.02. Our result also indicates that there are small volumes (less than 1% volume fraction) with very high In mole fraction.

Experimental investigation of photonic band gap influence on enhancement of Raman-scattering in metal-dielectric colloidal crystals

2012 ◽  
Vol 112 (8) ◽  
pp. 084303 ◽  
Author(s):  
Sriram Guddala ◽  
Shadak Alee Kamanoor ◽  
Andrea Chiappini ◽  
Maurizio Ferrari ◽  
Narayana Rao Desai
Keyword(s):  
Experimental Investigation ◽  
Raman Scattering ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Colloidal Crystals ◽  
Photonic Band

Point Defects in Relaxed Si1-xGex Alloy Layers

1998 ◽  
Vol 510 ◽  
Author(s):  
A. Mesli ◽  
A. Nylandsted Larsen
Keyword(s):  
Thermal Stability ◽  
Point Defect ◽  
Band Gap ◽  
Charge State ◽  
Point Defects ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
Band Gap Engineering ◽  
The Impact ◽  
Thermal Stability Of

AbstractThe use of compositionally graded buffer layers in the growth of fully relaxed epitaxial Si1−xGex alloy layers has led to a major improvement in crystalline quality. A considerable reduction in the density of the threading dislocations has become possible, facilitating point defect studies in these materials. The issues addressed in this review are inherent to the coupling between band gap engineering and defect-related levels. Among them, the pinning behaviour, charge state effects and their consequence upon the thermal stability of point defects are discussed together with the impact of the fluctuation in Ge distribution

Sign in / Sign up

Export Citation Format

Share Document