Electron-phonon scattering and anisotropy of conductivity in quasi-two-dimensional systems

Resistivity temperature â€“ dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron â€“ dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

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Electron-phonon scattering in β-Ga2O3 studied by ultrafast transmission spectroscopy

Applied Physics Letters ◽

10.1063/5.0053845 ◽

2021 ◽

Vol 118 (24) ◽

pp. 242107

Author(s):

Saulius Marcinkevičius ◽

James S. Speck

Keyword(s):

Phonon Scattering ◽

Transmission Spectroscopy ◽

Electron Phonon Scattering

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Manipulation of hot carrier cooling dynamics in two-dimensional Dion–Jacobson hybrid perovskites via Rashba band splitting

Nature Communications ◽

10.1038/s41467-021-24258-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jun Yin ◽

Rounak Naphade ◽

Partha Maity ◽

Luis Gutiérrez-Arzaluz ◽

Dhaifallah Almalawi ◽

...

Keyword(s):

Transient Absorption ◽

Phonon Scattering ◽

Transient Absorption Spectroscopy ◽

Band Model ◽

Two Dimensional ◽

Spintronic Devices ◽

Hot Carrier ◽

Band Splitting ◽

Perovskite Materials ◽

Spin Polarized

AbstractHot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion–Jacobson hybrid perovskites, namely, (3AMP)PbI4 and (4AMP)PbI4 (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI4, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI4 can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.

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When band convergence is not beneficial for thermoelectrics

Nature Communications ◽

10.1038/s41467-021-23839-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Junsoo Park ◽

Maxwell Dylla ◽

Yi Xia ◽

Max Wood ◽

G. Jeffrey Snyder ◽

...

Keyword(s):

Charge Carrier ◽

First Principles ◽

Design Principle ◽

Phonon Scattering ◽

Charge Carrier Concentration ◽

Deformation Potential ◽

Interband Scattering ◽

Improved Performance ◽

Full Heusler ◽

Electron Phonon Scattering

AbstractBand convergence is considered a clear benefit to thermoelectric performance because it increases the charge carrier concentration for a given Fermi level, which typically enhances charge conductivity while preserving the Seebeck coefficient. However, this advantage hinges on the assumption that interband scattering of carriers is weak or insignificant. With first-principles treatment of electron-phonon scattering in the CaMg2Sb2-CaZn2Sb2 Zintl system and full Heusler Sr2SbAu, we demonstrate that the benefit of band convergence can be intrinsically negated by interband scattering depending on the manner in which bands converge. In the Zintl alloy, band convergence does not improve weighted mobility or the density-of-states effective mass. We trace the underlying reason to the fact that the bands converge at a one k-point, which induces strong interband scattering of both the deformation-potential and the polar-optical kinds. The case contrasts with band convergence at distant k-points (as in the full Heusler), which better preserves the single-band scattering behavior thereby successfully leading to improved performance. Therefore, we suggest that band convergence as thermoelectric design principle is best suited to cases in which it occurs at distant k-points.

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