Probing the interlayer excitation dynamics in WS2/WSe2 heterostructures with broadly tunable pump and probe energies.
Nanoscale
; 15(48): 19777-19783, 2023 Dec 14.
Article
em En
| MEDLINE
| ID: mdl-38050459
ABSTRACT
van der Waals heterostructures based on transition metal dichalcogenides (TMDs) provide a fascinating platform for exploring new physical phenomena and novel optoelectronic functionalities. Revealing the energy-dependence of photocarrier population dynamics in heterostructures is key for developing optoelectronic or valleytronic devices. Here, the broadband transient dynamics of interlayer excitation of a nearly-aligned WS2/WSe2 heterostructure is investigated by using energy-dependent pump-probe spectroscopy at cryogenic temperatures. Interestingly, WS2/WSe2 interlayer excitation, herein comprising a mixture of intra- and inter-layer excitons, exhibits largely constant lifetimes of a few hundred picoseconds across a broad energy range, in stark contrast to the salient energy-dependent dynamics of intralayer excitons in monolayer WSe2. While the PL emission of the WS2/WSe2 heterostructure is found to be strongly affected by electrostatic doping, the lifetimes of interlayer excitation show negligible changes. Our work elaborates the signatures of ultrafast dynamics introduced by intra- and interlayer co-existing excitonic species and enriches the understanding of interlayer couplings in van der Waals heterostructures.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nanoscale
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China