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Photoexcited terahertz conductivity dynamics of graphene tuned by oxygen-adsorption

Journal Article


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Abstract


  • By using optical pump-terahertz (THz) probe spectroscopy, the photoexcited terahertz conductivity dynamics of chemical vapor deposition grown graphene is investigated in different atmospheric environments. It is shown that the Fermi energy of doped graphene is engineered by oxygen adsorption and desorption, which is probed by transient THz conductivity measurement. We show that the ultrafast energy relaxation processes depend on Fermi energy (changed by environmental gas) and the density of excited carriers (changed by photo-excitation fluence). The rise process of the negative conductivity dynamics becomes less efficient upon decreasing the Fermi energy and/or increasing the pump fluence. All findings show that the Fermi energy of graphene engineered by environmental gas allows us to tune the ultrafast energy relaxation pathways in photoexcited graphene.

UOW Authors


  •   Zhang, Zeyu (external author)
  •   Lin, Tie (external author)
  •   Xing, Xiao (external author)
  •   Lin, Xian (external author)
  •   Meng, Xiangjian (external author)
  •   Cheng, Zhenxiang
  •   Jin, Zuanming (external author)
  •   Ma, Guohong (external author)

Publication Date


  • 2017

Citation


  • Zhang, Z., Lin, T., Xing, X., Lin, X., Meng, X., Cheng, Z., Jin, Z. & Ma, G. (2017). Photoexcited terahertz conductivity dynamics of graphene tuned by oxygen-adsorption. Applied Physics Letters, 110 (11), 111108-1-111108-5.

Scopus Eid


  • 2-s2.0-85016165437

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3492&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2468

Start Page


  • 111108-1

End Page


  • 111108-5

Volume


  • 110

Issue


  • 11

Abstract


  • By using optical pump-terahertz (THz) probe spectroscopy, the photoexcited terahertz conductivity dynamics of chemical vapor deposition grown graphene is investigated in different atmospheric environments. It is shown that the Fermi energy of doped graphene is engineered by oxygen adsorption and desorption, which is probed by transient THz conductivity measurement. We show that the ultrafast energy relaxation processes depend on Fermi energy (changed by environmental gas) and the density of excited carriers (changed by photo-excitation fluence). The rise process of the negative conductivity dynamics becomes less efficient upon decreasing the Fermi energy and/or increasing the pump fluence. All findings show that the Fermi energy of graphene engineered by environmental gas allows us to tune the ultrafast energy relaxation pathways in photoexcited graphene.

UOW Authors


  •   Zhang, Zeyu (external author)
  •   Lin, Tie (external author)
  •   Xing, Xiao (external author)
  •   Lin, Xian (external author)
  •   Meng, Xiangjian (external author)
  •   Cheng, Zhenxiang
  •   Jin, Zuanming (external author)
  •   Ma, Guohong (external author)

Publication Date


  • 2017

Citation


  • Zhang, Z., Lin, T., Xing, X., Lin, X., Meng, X., Cheng, Z., Jin, Z. & Ma, G. (2017). Photoexcited terahertz conductivity dynamics of graphene tuned by oxygen-adsorption. Applied Physics Letters, 110 (11), 111108-1-111108-5.

Scopus Eid


  • 2-s2.0-85016165437

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3492&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2468

Start Page


  • 111108-1

End Page


  • 111108-5

Volume


  • 110

Issue


  • 11