Exciton Relaxation Cascade in two-dimensional Transition Metal Dichalcogenides
Artikel i vetenskaplig tidskrift, 2018

Monolayers of transition metal dichalcogenides (TMDs) are characterized by an extraordinarily strong Coulomb interaction giving rise to tightly bound excitons with binding energies of hundreds of meV. Excitons dominate the optical response as well as the ultrafast dynamics in TMDs. As a result, a microscopic understanding of exciton dynamics is the key for a technological application of these materials. In spite of this immense importance, elementary processes guiding the formation and relaxation of excitons after optical excitation of an electron-hole plasma has remained unexplored to a large extent. Here, we provide a fully quantum mechanical description of momentum- and energy-resolved exciton dynamics in monolayer molybdenum diselenide (MoSe2) including optical excitation, formation of excitons, radiative recombination as well as phonon-induced cascade-like relaxation down to the excitonic ground state. Based on the gained insights, we reveal experimentally measurable features in pump-probe spectra providing evidence for the exciton relaxation cascade.

Författare

Samuel Brem

Chalmers, Fysik, Kondenserade materiens teori

Malte Selig

Technische Universität Berlin

Gunnar Berghäuser

Chalmers, Fysik, Kondenserade materiens teori

Ermin Malic

Chalmers, Fysik, Kondenserade materiens teori

Scientific Reports

2045-2322 (ISSN)

Vol. 8 8238

Graphene Core1. Graphene-based disruptive technologies (Graphene Flagship)

Europeiska kommissionen (Horisont 2020), 2016-04-01 -- 2018-03-31.

Ämneskategorier

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.1038/s41598-018-25906-7

PubMed

29844321

Mer information

Senast uppdaterat

2018-09-05