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Colloidal semiconductor nanoplatelets, in which carriers are strongly confined only along one dimension, present fundamentally different excitonic properties than quantum dots, which support strong confinement in all three dimensions. In…

Mesoscale and Nanoscale Physics · Physics 2020-01-08 Daniel Amgar , Gaoling Yang , Ron Tenne , Dan Oron

The question of macroscopic occupation and spontaneous emergence of coherence for exciton ensembles has gained renewed attention due to the rise of van der Waals heterostructures made of atomically thin semiconductors. The hosted interlayer…

We propose a theoretical approach based on (constrained) density functional theory and the Franck-Condon approximation for the calculation of the temperature dependent photoluminescence of nanostructures. The method is computationally…

Mesoscale and Nanoscale Physics · Physics 2023-11-20 Peng Han , Gabriel Bester

We demonstrate significant cooling of electrons in a nanostructure below 10 mK by demagnetisation of thin-film copper on a silicon chip. Our approach overcomes the typical bottleneck of weak electron-phonon scattering by coupling the…

Electron-hole pairs in semiconductors are essential for solar cells and fast electronic circuitry, but the competition between carrier transport and relaxation into heat limits the efficiency and speed. Here we use ultrafast electron…

Materials Science · Physics 2025-02-27 A. B. Swain , J. Kuttruff , J. Vorberger , P. Baum

Exciton-phonon coupling limits the homogeneous emission linewidth of nanocrystals. Hence, a full understanding of it is crucial. In this work, we statistically investigate exciton-phonon coupling by performing single-particle spectroscopy…

It appears feasible with nanostructures to perform calorimetry at the level of individual thermal phonons. Here I outline an approach employing monocrystalline mesoscopic insulators, which can now be patterned from semiconductor…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. L. Roukes

Theoretical and numerical calculations of the optical absorption spectra of excitons interacting with longitudinal-optical phonons in quasi-2D polar semiconductors are presented. In II-VI semiconductor quantum wells, exciton binding energy…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 F. J. Rodriguez

We predict a strong enhancement of the critical temperature in a conventional Bardeen-Cooper-Schrieffer (BCS) superconductor in the presence of a bosonic condensate of exciton-polaritons. The effect depends strongly on the ratio of the…

Superconductivity · Physics 2018-03-14 Petros Skopelitis , Evgenia D. Cherotchenko , Alexey V. Kavokin , Anna Posazhennikova

Non-radiative exciton relaxation processes are critical for energy transduction efficiencies in optoelectronic materials, but how these processes are connected to the underlying crystal structure and its associated electron, exciton, and…

Materials Science · Physics 2023-05-09 Galit Cohen , Jonah B. Haber , Jeffrey B. Neaton , Diana Y. Qiu , Sivan Refaely-Abramson

While using first-principles-based Boltzmann transport equation approach to predict the thermal conductivity of crystalline semiconductor materials has been a routine, the validity of the approach is seldom tested for high-temperature…

Mesoscale and Nanoscale Physics · Physics 2020-03-05 Xiaokun Gu , Shouhang Li , Hua Bao

The picosecond dynamics of excitons in colloidal CdSe nanorods are directly measured via their 1s to 2p-like internal transitions by ultra-broadband terahertz spectroscopy. Broadened absorption peaks from both the longitudinal and…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 David G. Cooke , Peter Uhd Jepsen , Jun Yan Lek , Yeng Ming Lam , Fredrik Sy , Marc M. Dignam

Phonons, the quanta of lattice vibrations, are primary heat carriers for semiconductors and dielectrics. The demand of effective phonon manipulation urgently emerges, because the thermal management is crucial for the ongoing development of…

Electron-phonon relaxation in size-quantized systems may become inhibited when the spacing of discrete electron energy levels exceeds the magnitude of the phonon frequency. We show, however, that nanoclusters can support a fast nonradiative…

Atomic and Molecular Clusters · Physics 2007-05-23 Vitaly V. Kresin , Yu. N. Ovchinnikov

Many promising optoelectronic devices, such as broadband photodetectors, nonlinear frequency converters, and building blocks for data communication systems, exploit photoexcited charge carriers in graphene. For these systems, it is…

Heterostructures of layered transition metal dichalcogenides (TMDs) host long-lived, tunable excitons, making them intriguing candidates for material-based quantum information applications. Light absorption in these systems induces a…

Materials Science · Physics 2023-08-25 Tomer Amit , Sivan Refaely-Abramson

Control of heat flux at small length scales is crucial for numerous solid-state devices and systems. In addition to the thermal management of information and communication devices the mastering of heat transfer channels down to the…

The relaxation of strongly-confined electrons and holes between 1P and 1S levels in colloidal PbSe nanocrystals has been time-resolved using femtosecond transient absorption spectroscopy. In contrast to II-VI and III-V semiconductor…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Jeffrey M. Harbold , Frank W. Wise , Hui Du , Todd D. Krauss , Kyung-Sang Cho , Chris B. Murray

The transport properties of hot holes in silicon at cryogenic temperatures exhibit several anomalous features, including the emergence of two distinct saturated drift velocity regimes and a non-monotonic trend of the current noise versus…

Materials Science · Physics 2023-06-28 David S. Catherall , Austin J. Minnich

Electron-phonon ($e$-ph) interactions are key to understanding the dynamics of electrons in materials, and can be modeled accurately from first-principles. However, when electrons and holes form Coulomb-bound states (excitons), quantifying…

Materials Science · Physics 2020-09-09 Hsiao-Yi Chen , Davide Sangalli , Marco Bernardi