Exciton Propagation and Halo Formation in Two-Dimensional Materials
Artikel i vetenskaplig tidskrift, 2019

The interplay of optics, dynamics, and transport is crucial for the design of novel optoelectronic devices, such as photodetectors and solar cells. In this context, transition-metal dichalcogenides (TMDs) have received much attention. Here, strongly bound excitons dominate optical excitation, carrier dynamics, and diffusion processes. While the first two have been intensively studied, there is a lack of fundamental understanding of nonequilibrium phenomena associated with exciton transport that is of central importance (e.g., for high-efficiency light harvesting). In this work, we provide microscopic insights into the interplay of exciton propagation and many-particle interactions in TMDs. On the basis of a fully quantum mechanical approach and in excellent agreement with photoluminescence measurements, we show that Auger recombination and emission of hot phonons act as a heating mechanism giving rise to strong spatial gradients in excitonic temperature. The resulting thermal drift leads to an unconventional exciton diffusion characterized by spatial exciton halos.

Auger scattering

hot phonons

exciton diffusion



Raul Perea Causin

Chalmers, Fysik, Kondenserade materiens teori

Samuel Brem

Chalmers, Fysik, Kondenserade materiens teori

Roberto Rosati

Chalmers, Fysik, Kondenserade materiens teori

Roland Jago

Chalmers, Fysik, Kondenserade materiens teori

Marvin Kulig

Universität Regensburg

Jonas D. Ziegler

Universität Regensburg

Jonas Zipfel

Universität Regensburg

A. Chernikov

Universität Regensburg

Ermin Malic

Chalmers, Fysik, Kondenserade materiens teori

Nano Letters

1530-6984 (ISSN) 1530-6992 (eISSN)

Vol. 19 10 7317-7323


Atom- och molekylfysik och optik

Annan fysik

Den kondenserade materiens fysik





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