Exciton Propagation and Halo Formation in Two-Dimensional Materials
Journal article, 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, Physics, Condensed Matter Theory

Samuel Brem

Chalmers, Physics, Condensed Matter Theory

Roberto Rosati

Chalmers, Physics, Condensed Matter Theory

Roland Jago

Chalmers, Physics, Condensed Matter Theory

Marvin Kulig

University of Regensburg

Jonas D. Ziegler

University of Regensburg

Jonas Zipfel

University of Regensburg

A. Chernikov

University of Regensburg

Ermin Malic

Chalmers, Physics, Condensed Matter Theory

Nano Letters

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

Vol. 19 10 7317-7323

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics





More information

Latest update