Biexcitons do not form in MoS2 monolayers from optical pumping at 6 K

Ryan E. Wood, Lawson T. Lloyd, Fauzia Mujid, Lili Wang, Marco A. Allodi, Hui Gao, Richard Mazuski, Po Chieh Ting, Saien Xie, Jiwoong Park, Gregory S. Engel

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Transition metal dichalcogenides (TMDs) have attracted much interest in recent years due to their emerging material properties. In monolayer TMDs, such as MoS2, extreme quantum confinement is achieved in the monolayer limit. Although monolayer TMDs represent an ideal platform to explore excitonic physics using ultrafast spectroscopy, this exploration is currently limited by confusion regarding the origin of certain spectral features, including the below-bandgap PIA feature observed in pump-probe experiments. In this work, we document an absence of PIA features immediately after photoexcitation, indicating a lack of strong optically-induced biexciton formation. Below-bandgap PIA features are observed to grow in with a time constant of 110 ± 10 fs, indicative of other factors responsible for their origin. These results indicate that optically-induced biexciton formation is most likely not responsible for the previously observed PIA features in MoS2 monolayers.

Original languageEnglish (US)
Title of host publicationUltrafast Phenomena and Nanophotonics XXIV
EditorsMarkus Betz, Abdulhakem Y. Elezzabi
ISBN (Electronic)9781510633193
StatePublished - 2020
Externally publishedYes
EventUltrafast Phenomena and Nanophotonics XXIV 2020 - San Francisco, United States
Duration: Feb 2 2020Feb 4 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceUltrafast Phenomena and Nanophotonics XXIV 2020
Country/TerritoryUnited States
CitySan Francisco

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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