Exciton tuning in monolayer WSe2 via substrate induced electron doping

Publikationen: Beitrag in FachzeitschriftArtikelForschung(peer-reviewed)

Autoren

  • Yang Pan
  • Mahfujur Rahaman
  • Lu He
  • Ilya Milekhin
  • Gopinath Manoharan
  • Thomas Blaudeck
  • Andreas Willert
  • Teresa I. Madeira
  • Dietrich R.T. Zahn

Organisationseinheiten

Externe Organisationseinheiten

  • Technische Universität Chemnitz
  • University of Pennsylvania
  • Fraunhofer-Institut für Elektronische Nanosysteme ENAS

Abstract

We report large exciton tuning in WSe2 monolayers via substrate induced non-degenerate doping. We observe a redshift of ∼62 meV for the A exciton together with a 1–2 orders of magnitude photoluminescence (PL) quenching when the monolayer WSe2 is brought in contact with highly oriented pyrolytic graphite (HOPG) compared to dielectric substrates such as hBN and SiO2. As the evidence of doping from HOPG to WSe2, a drastic increase of the intensity ratio of trions to neutral excitons was observed. Using a systematic PL and Kelvin probe force microscopy (KPFM) investigation on WSe2/ HOPG, WSe2/hBN, and WSe2/graphene, we conclude that this unique excitonic behavior is induced by
electron doping from the substrate. Our results propose a simple yet efficient way for exciton tuning in monolayer WSe2, which plays a central role in the fundamental understanding and further device development.

Details

OriginalspracheEnglisch
Seitenumfang7
FachzeitschriftNanoscale advances
Jahrgang2022
Ausgabenummer23
DOIs
StatusElektronische Veröffentlichung vor Drucklegung. - 25 Okt. 2022