Probing exciton species in atomically thin WS2-graphene heterostructures

Cristina E. Giusca, Zhong Lin, Mauricio Terrones, D. Kurt Gaskill, Rachael L. Myers-Ward, Olga Kazakova

Research output: Contribution to journalArticlepeer-review

Abstract

We report on a detailed study of temperature-dependent photoluminescence spectroscopy of monolayer WS2 grown on epitaxial graphene. The study reveals for the first time the intrinsic excitonic effects of WS2 supported on one- and two-layer graphene (2LG) from room temperature to 83 K, with both excitons and trions evidenced in the entire temperature range and temperature-independent trion dissociation. All emission peaks exhibit a shift towards higher energy with decreasing temperature due to band gap renormalisation induced by electron-phonon interaction. A highly linear dependence of the photoluminescence with the excitation power is found for both WS2 on one- and 2LG, confirming the excitonic nature of associated transitions and the high crystal quality of the WS2-graphene heterostructure.

Original languageEnglish (US)
Article number025001
JournalJPhys Materials
Volume2
Issue number2
DOIs
StatePublished - Apr 2019

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics

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