Photoluminescence emission and Raman response of monolayer MoS₂, MoSe₂, and WSe₂

Opt Express. 2013 Feb 25;21(4):4908-16. doi: 10.1364/OE.21.004908.


We mechanically exfoliate mono- and few-layers of the transition metal dichalcogenides molybdenum disulfide, molybdenum diselenide, and tungsten diselenide. The exact number of layers is unambiguously determined by atomic force microscopy and high-resolution Raman spectroscopy. Strong photoluminescence emission is caused by the transition from an indirect band gap semiconductor of bulk material to a direct band gap semiconductor in atomically thin form.

MeSH terms

  • Light
  • Luminescent Measurements / methods*
  • Materials Testing
  • Scattering, Radiation
  • Spectrum Analysis, Raman / methods*
  • Transition Elements / chemistry*
  • Transition Elements / radiation effects


  • Transition Elements