Tailoring the optical properties of atomically-thin WS2: Via ion irradiation

Research output: Contribution to journalArticle

Researchers

  • L. Ma
  • Cindy S.Y. Tan
  • M. Ghorbani-Asl
  • R. Boettger
  • Silvan Kretschmer
  • S. Zhou
  • Z. Huang
  • Arkady Krasheninnikov

  • F. Chen

Research units

  • Shandong University
  • Helmholtz-Zentrum Dresden-Rossendorf
  • XiangTan University

Abstract

Two-dimensional transition metal dichalcogenides (TMDCs) exhibit excellent optoelectronic properties. However, the large band gaps in many semiconducting TMDCs make optical absorption in the near-infrared (NIR) wavelength regime impossible, which prevents applications of these materials in optical communications. In this work, we demonstrate that Ar+ ion irradiation is a powerful post-synthesis technique to tailor the optical properties of the semiconducting tungsten disulfide (WS2) by creating S-vacancies and thus controlling material stoichiometry. First-principles calculations reveal that the S-vacancies give rise to deep states in the band gap, which determine the NIR optical absorption of the WS2 monolayer. As the density of the S-vacancies increases, the enhanced NIR linear and saturable absorption of WS2 is observed, which is explained by the results of first-principles calculations. We further demonstrate that by using the irradiated WS2 as a saturable absorber in a waveguide system, the passively Q-switched laser operations can be optimized, thus opening new avenues for tailoring the optical response of TMDCs by defect-engineering through ion irradiation.

Details

Original languageEnglish
Pages (from-to)11027-11034
Number of pages8
JournalNanoscale
Volume9
Issue number31
Publication statusPublished - 21 Aug 2017
MoE publication typeA1 Journal article-refereed

ID: 14874558