Probing the Spin-Polarized Electronic Band Structure in Monolayer Transition Metal Dichalcogenides by Optical Spectroscopy

Zefang Wang, Liang Zhao, Kin Fai Mak, Jie Shan

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

Abstract

We study the electronic band structure in the K/K′ valleys of the Brillouin zone of monolayer WSe2 and MoSe2 by optical reflection and photoluminescence spectroscopy on dual-gated field-effect devices. Our experiment reveals the distinct spin polarization in the conduction bands of these compounds by a systematic study of the doping dependence of the A and B excitonic resonances. Electrons in the highest-energy valence band and the lowest-energy conduction band have antiparallel spins in monolayer WSe2 and parallel spins in monolayer MoSe2. The spin splitting is determined to be hundreds of meV for the valence bands and tens of meV for the conduction bands, which are in good agreement with first-principles calculations. These values also suggest that both n- and p-type WSe2 and MoSe2 can be relevant for spin- and valley-based applications.

Original languageEnglish (US)
Pages (from-to)740-746
Number of pages7
JournalNano letters
Volume17
Issue number2
DOIs
StatePublished - Feb 8 2017

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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