Distinct photoluminescence and Raman spectroscopy signatures for identifying highly crystalline WS2 monolayers produced by different growth methods

Amber McCreary, Ayse Berkdemir, Junjie Wang, Minh An Nguyen, Ana Laura Elías, Néstor Perea-López, Kazunori Fujisawa, Bernd Kabius, Victor Carozo, David A. Cullen, Thomas E. Mallouk, J. Zhu, Mauricio Terrones

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

Transition metal dichalcogenides such as WS2 show exciting promise in electronic and optoelectronic applications. Significant variations in the transport, Raman, and photoluminescence (PL) can be found in the literature, yet it is rarely addressed why this is. In this report, Raman and PL of monolayered WS2 produced via different methods are studied and distinct features that indicate the degree of crystallinity of the material are observed. While the intensity of the LA(M) Raman mode is found to be a useful indicator to assess the crystallinity, PL is drastically more sensitive to the quality of the material than Raman spectroscopy. We also show that even exfoliated crystals, which are usually regarded as the most pristine material, can contain large amounts of defects that would not be apparent without Raman and PL measurements. These findings can be applied to the understanding of other two-dimensional heterostructured systems.

Original languageEnglish (US)
Pages (from-to)931-944
Number of pages14
JournalJournal of Materials Research
Volume31
Issue number7
DOIs
StatePublished - Apr 14 2016

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this