Electron-Phonon Coupling, Coulomb Pseudo Potential µ* and Physical Properties of C60 Compounds

1994 ◽  
pp. 263-285
Author(s):  
O. Gunnarsson ◽  
V. P. Antropov ◽  
J. Fink ◽  
M. S. Golden ◽  
M. Knupfer ◽  
...  
Keyword(s):  
Physical Properties ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Pseudo Potential

Predicting high thermoelectric performance of ABX ternary compounds NaMgX (X = P, Sb, As) with weak electron–phonon coupling and strong bonding anharmonicity

2016 ◽  
Vol 4 (15) ◽  
pp. 3281-3289 ◽  
Author(s):  
A. J. Hong ◽  
J. J. Gong ◽  
L. Li ◽  
Z. B. Yan ◽  
Z. F. Ren ◽  
...  
Keyword(s):  
Physical Properties ◽  
Thermoelectric Performance ◽  
Phonon Coupling ◽  
Ternary Compounds ◽  
Electron Phonon Coupling ◽  
Weak Electron

The ABX ternary compounds have a variety of attractive physical properties.

scholarly journals Investigations of Electron-Electron and Interlayer Electron-Phonon Coupling in van der Waals hBN/WSe2/hBN Heterostructures by Photoluminescence Excitation Experiments

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 399
Author(s):  
Joanna Jadczak ◽  
Joanna Kutrowska-Girzycka ◽  
Janina J. Schindler ◽  
Joerg Debus ◽  
Kenji Watanabe ◽  
...  
Keyword(s):  
Physical Properties ◽  
Emission Intensity ◽  
Van Der Waals ◽  
Double Resonance ◽  
Strong Increase ◽  
Exciting Light ◽  
Photoluminescence Excitation ◽  
Phonon Coupling ◽  
Excitation Light ◽  
Electron Phonon Coupling

Monolayers of transition metal dichalcogenides (TMDs) with their unique physical properties are very promising for future applications in novel electronic devices. In TMDs monolayers, strong and opposite spin splittings of the energy gaps at the K points allow for exciting carriers with various combinations of valley and spin indices using circularly polarized light, which can further be used in spintronics and valleytronics. The physical properties of van der Waals heterostructures composed of TMDs monolayers and hexagonal boron nitride (hBN) layers significantly depend on different kinds of interactions. Here, we report on observing both a strong increase in the emission intensity as well as a preservation of the helicity of the excitation light in the emission from hBN/WSe2/hBN heterostructures related to interlayer electron-phonon coupling. In combined low-temperature (T = 7 K) reflectivity contrast and photoluminescence excitation experiments, we find that the increase in the emission intensity is attributed to a double resonance, where the laser excitation and the combined Raman mode A′1 (WSe2) + ZO (hBN) are in resonance with the excited (2s) and ground (1s) states of the A exciton in a WSe2 monolayer. In reference to the 2s state, our interpretation is in contrast with previous reports, in which this state has been attributed to the hybrid exciton state existing only in the hBN-encapsulated WSe2 monolayer. Moreover, we observe that the electron-phonon coupling also enhances the helicity preservation of the exciting light in the emission of all observed excitonic complexes. The highest helicity preservation of more than 60% is obtained in the emission of the neutral biexciton and negatively charged exciton (trion) in its triplet state. Additionally, to the best of our knowledge, the strongly intensified emission of the neutral biexciton XX0 at double resonance condition is observed for the first time.

Self-Energy Analysis of Infrared Conductivity of Normal State MgB2

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3534-3539 ◽  
Author(s):  
Han-Yong Choi ◽  
Tae-Hyoung Gimm
Keyword(s):  
Physical Properties ◽  
Normal State ◽  
Energy Analysis ◽  
Plasma Frequency ◽  
Effective Interaction ◽  
The Self ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Self Energy ◽  
Electron Phonon Coupling

The self-energy analysis of the frequency-dependent infrared conductivity σ(ω) of MgB 2 in normal state is presented. Experimentally obtained σ(ω) is inverted to yield the self-energy of electrons. From the extracted self-energy, other physical properties such as the effective interaction between electrons can also be computed. We suggest from the self-energy analysis that the small electron-phonon coupling constant of MgB 2 obtained previously can be attributed to an underestimate of the plasma frequency.

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.

scholarly journals Structural phase transition and superconductivity hierarchy in 1T-TaS2 under pressure up to 100 GPa

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Qing Dong ◽  
Quanjun Li ◽  
Shujia Li ◽  
Xuhan Shi ◽  
Shifeng Niu ◽  
...  
Keyword(s):  
Structural Phase ◽  
Transition Metal Dichalcogenides ◽  
Phonon Coupling ◽  
Structural Phase Transitions ◽  
Strong Electron ◽  
Electron Phonon Coupling ◽  
Increasing Trend ◽  
Metal Dichalcogenides ◽  
Dome Shape ◽  
Enhanced Superconductivity

AbstractThe adoption of high pressure not only reinforces the comprehension of the structure and exotic electronic states of transition metal dichalcogenides (TMDs) but also promotes the discovery of intriguing phenomena. Here, 1T-TaS2 was investigated up to 100 GPa, and re-enhanced superconductivity was found with structural phase transitions. The discovered I4/mmm TaS2 presents strong electron–phonon coupling, revealing a good superconductivity of the nonlayered structure. The P–T phase diagram shows a dome shape centered at ~20 GPa, which is attributed to the distortion of the 1T structure. Accompanied by the transition to nonlayered structure above 44.5 GPa, the superconducting critical temperature shows an increasing trend and reaches ~7 K at the highest studied pressure, presenting superior superconductivity compared to the original layered structure. It is unexpected that the pressure-induced re-enhanced superconductivity was observed in TMDs, and the transition from a superconductor with complicated electron-pairing mechanism to a phonon-mediated superconductor would expand the field of pressure-modified superconductivity.

Ab Initio Study of the Electron–Phonon Coupling in Ultrathin Al Layers

2021 ◽  
Vol 203 (1-2) ◽  
pp. 180-193
Author(s):  
S. Giaremis ◽  
Ph. Komninou ◽  
Th. Karakostas ◽  
J. Kioseoglou
Keyword(s):  
Ab Initio ◽  
Ab Initio Study ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

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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