Interlayer exciton dynamics in van der Waals heterostructures
Artikel i vetenskaplig tidskrift, 2019

Atomically thin transition metal dichalcogenides can be stacked to van der Waals heterostructures enabling the design of new materials with tailored properties. The strong Coulomb interaction gives rise to interlayer excitons, where electrons and holes are spatially separated in different layers. In this work, we reveal the time- and momentum-dependent elementary processes behind the formation, thermalization and photoemission of interlayer excitons for the exemplary MoSe2-WSe2 heterostructure. We identify tunneling of holes from MoSe2 to WSe2 on a ps timescale as the crucial process for interlayer exciton formation. We also predict a drastic reduction of the formation time as a function of the interlayer energy offset suggesting that interlayer excitons can be externally tuned. Finally, we explain the experimental observation of a dominant photoluminescence from interlayer excitons despite the vanishingly small oscillator strength as a consequence of huge interlayer exciton occupations at low temperatures.

Författare

Simon Ovesen

Chalmers, Fysik, Kondenserade materiens teori

Samuel Brem

Chalmers, Fysik, Kondenserade materiens teori

Christopher Linderälv

Chalmers, Fysik, Material- och ytteori

Mikael Juhani Kuisma

Chalmers, Fysik, Material- och ytteori

Tobias Korn

Universität Rostock

Paul Erhart

Chalmers, Fysik, Material- och ytteori

Malte Selig

Technische Universität Berlin

Ermin Malic

Chalmers, Fysik, Kondenserade materiens teori

Communications Physics

2399-3650 (ISSN)

Vol. 2 23

Ämneskategorier

Materialkemi

Annan fysik

Den kondenserade materiens fysik

DOI

10.1038/s42005-019-0122-z

Mer information

Senast uppdaterat

2019-05-06