Resonant Raman technique-a powerful tool for exploring electron-phonon coupling in Se nanoclusters

2006 ◽  
Author(s):  
Irene Ling Li ◽  
Jian Pang Zhai ◽  
Zi Kang Tang ◽  
Shuang Chen Ruan ◽  
Min Zhang
Keyword(s):  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Resonant Raman

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.

Enhanced Resonant Raman Scattering and Electron−Phonon Coupling from Self-Assembled Secondary ZnO Nanoparticles

2005 ◽  
Vol 109 (39) ◽  
pp. 18385-18390 ◽  
Author(s):  
Hsin-Ming Cheng ◽  
Kuo-Feng Lin ◽  
Hsu ◽  
Chih-Jen Lin ◽  
Li-Jiaun Lin ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Zno Nanoparticles ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Resonant Raman ◽  
Resonant Raman Scattering ◽  
Self Assembled

Resonant Raman scattering and electron-phonon coupling in the organic superconductor (BEDT-TTF)2[Cu(NCS)2]

1997 ◽  
Vol 86 (1-3) ◽  
pp. 2067-2068 ◽  
Author(s):  
J.E. Eldridge ◽  
Y. Xie ◽  
Y. Lin ◽  
H.H. Wang ◽  
J.M. Williams ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Organic Superconductor ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Resonant Raman ◽  
Resonant Raman Scattering

scholarly journals Phonon Spectra of Small Colloidal II-VI Semiconductor Nanocrystals

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Volodymyr Dzhagan ◽  
Mykhailo Valakh ◽  
Nikolai Mel'nik ◽  
Olexandra Rayevska ◽  
Irina Lokteva ◽  
...  
Keyword(s):  
Semiconductor Nanocrystals ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Coupling ◽  
Phonon Modes ◽  
Phonon Spectra ◽  
Electron Phonon Coupling ◽  
Unified View ◽  
Resonant Raman ◽  
Broad Feature

Resonant Raman spectroscopy has been employed to explore the first- and higher-order phonon spectra of several kinds of II-VI nanocrystals (NCs), with the aim of better understanding of the nature of phonon modes and forming a unified view onto the vibrational spectrum of semiconductor NCs. Particularly, besides the previously discussed TO, SO, LO, and 2LO modes, the combinational modes of TO+LO and SO+LO can be assumed to account for the lineshape of the spectrum below 2LO band. No trace of 2TO or 2SO band was detected, what can be the result of the dominance of Fröhlich mechanism in electron-phonon coupling in II-VI compounds. The resonant phonon Raman spectrum of NCs smaller than 2 nm is shown to be dominated by a broad feature similar to the SO mode of larger NCs or phonon density of states of a bulk crystal.

Resonant Raman Scattering in CdSxSe1−x Nanocrystals: Electron-Phonon Coupling

1994 ◽  
Vol 358 ◽  
Author(s):  
M. Silvestri ◽  
L.W. Hwang ◽  
P. Persans ◽  
J. Schroeder
Keyword(s):  
Phase Transition ◽  
Raman Scattering ◽  
Coupling Strength ◽  
Phonon Coupling ◽  
Transition Pressure ◽  
Pressure Point ◽  
Phase Transition Pressure ◽  
Electron Phonon Coupling ◽  
Resonant Raman ◽  
Resonant Raman Scattering

ABSTRACTWe report pressure and laser tuned Raman scattering studies on CdSxSei1-x nanocrystals. The electron-phonon coupling strength was determined as a function of pressure beyond the bulk phase transition pressure point. The coupling strength at atmospheric pressure determined from the Stokes shifted photoluminescence and resonant Raman scattering is not drastically smaller than the bulk value as might be expected theoretically. As a function of pressure it also shows no abrupt changes at the bulk phase transition pressure point. These results indicate that deep traps play a critical part in the mechanism of the electron-phonon coupling.

Observation of Core Phonon in Electron–Phonon Coupling in Au25 Nanoclusters

2021 ◽  
Vol 12 (6) ◽  
pp. 1690-1695
Author(s):  
Zhongyu Liu ◽  
Yingwei Li ◽  
Wonyong Shin ◽  
Rongchao Jin
Keyword(s):  
Phonon Coupling ◽  
Electron Phonon Coupling

scholarly journals Electron-phonon coupling in the magnetic Weyl semimetal ZrCo2Sn

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
I.Yu. Sklyadneva ◽  
R. Heid ◽  
P. M. Echenique ◽  
E. V. Chulkov
Keyword(s):  
Phonon Coupling ◽  
Weyl Semimetal ◽  
Electron Phonon Coupling

scholarly journals Dielectric screening in perovskite photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rui Su ◽  
Zhaojian Xu ◽  
Jiang Wu ◽  
Deying Luo ◽  
Qin Hu ◽  
...  
Keyword(s):  
Open Circuit Voltage ◽  
Low Voltage ◽  
Power Conversion ◽  
Surface Recombination ◽  
Open Circuit ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Dielectric Screening ◽  
Perovskite Photovoltaic ◽  
Reduced Surface

AbstractThe performance of perovskite photovoltaics is fundamentally impeded by the presence of undesirable defects that contribute to non-radiative losses within the devices. Although mitigating these losses has been extensively reported by numerous passivation strategies, a detailed understanding of loss origins within the devices remains elusive. Here, we demonstrate that the defect capturing probability estimated by the capture cross-section is decreased by varying the dielectric response, producing the dielectric screening effect in the perovskite. The resulting perovskites also show reduced surface recombination and a weaker electron-phonon coupling. All of these boost the power conversion efficiency to 22.3% for an inverted perovskite photovoltaic device with a high open-circuit voltage of 1.25 V and a low voltage deficit of 0.37 V (a bandgap ~1.62 eV). Our results provide not only an in-depth understanding of the carrier capture processes in perovskites, but also a promising pathway for realizing highly efficient devices via dielectric regulation.

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