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Ultrafast photocarrier dynamics in a 3D Dirac semimetal Cd3As2 film studied with terahertz spectroscopy

Journal Article


Abstract


  • By employing optical pump Terahertz (THz) probe spectroscopy, a three dimensional (3D) Dirac semimetal, Cd3As2 film, was investigated systematically at room temperature. After photoexcitation at 400/800 nm, the rise time of photoenhanced THz photoconductivity (PC) is about ∼1.0 ps, increasing slightly with the pump fluence, in which time scale, photoexcited electrons and holes establish separate Fermi distribution with electrons in the conduction band and holes in the valence band via fast carrier-carrier scattering and carrier-phonon coupling. The subsequent THz PC relaxation shows single exponential decay with a time constant of ∼6.0 ps that is independent of pump fluence. The relaxation process is dominated by the electron-hole recombination via a radiative and nonradiative way, which is mediated by the phonon-phonon scattering. The optically induced THz complex PC can be well fitted with the Drude-Smith model. Our experimental results shed light on understanding the photocarrier dynamics of the 3D Dirac semimetal materials at THz frequency.

Authors


  •   Zhang, Wenjie (external author)
  •   Yang, Yunkun (external author)
  •   Suo, Peng (external author)
  •   Zhao, Wanying (external author)
  •   Guo, Jiajia (external author)
  •   Lu, Qi (external author)
  •   Lin, Xian (external author)
  •   Jin, Zuanming (external author)
  •   Wang, Lin (external author)
  •   Chen, Gang (external author)
  •   Xiu, Faxian (external author)
  •   Liu, Weimin (external author)
  •   Chao Zhang
  •   Ma, Guohong (external author)

Publication Date


  • 2019

Citation


  • Zhang, W., Yang, Y., Suo, P., Zhao, W., Guo, J., Lu, Q., Lin, X., Jin, Z., Wang, L., Chen, G., Xiu, F., Liu, W., Zhang, C. & Ma, G. (2019). Ultrafast photocarrier dynamics in a 3D Dirac semimetal Cd3As2 film studied with terahertz spectroscopy. Applied Physics Letters, 114 (22), 221102-1-221102-5.

Scopus Eid


  • 2-s2.0-85066837651

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers1/2868

Start Page


  • 221102-1

End Page


  • 221102-5

Volume


  • 114

Issue


  • 22

Place Of Publication


  • United States

Abstract


  • By employing optical pump Terahertz (THz) probe spectroscopy, a three dimensional (3D) Dirac semimetal, Cd3As2 film, was investigated systematically at room temperature. After photoexcitation at 400/800 nm, the rise time of photoenhanced THz photoconductivity (PC) is about ∼1.0 ps, increasing slightly with the pump fluence, in which time scale, photoexcited electrons and holes establish separate Fermi distribution with electrons in the conduction band and holes in the valence band via fast carrier-carrier scattering and carrier-phonon coupling. The subsequent THz PC relaxation shows single exponential decay with a time constant of ∼6.0 ps that is independent of pump fluence. The relaxation process is dominated by the electron-hole recombination via a radiative and nonradiative way, which is mediated by the phonon-phonon scattering. The optically induced THz complex PC can be well fitted with the Drude-Smith model. Our experimental results shed light on understanding the photocarrier dynamics of the 3D Dirac semimetal materials at THz frequency.

Authors


  •   Zhang, Wenjie (external author)
  •   Yang, Yunkun (external author)
  •   Suo, Peng (external author)
  •   Zhao, Wanying (external author)
  •   Guo, Jiajia (external author)
  •   Lu, Qi (external author)
  •   Lin, Xian (external author)
  •   Jin, Zuanming (external author)
  •   Wang, Lin (external author)
  •   Chen, Gang (external author)
  •   Xiu, Faxian (external author)
  •   Liu, Weimin (external author)
  •   Chao Zhang
  •   Ma, Guohong (external author)

Publication Date


  • 2019

Citation


  • Zhang, W., Yang, Y., Suo, P., Zhao, W., Guo, J., Lu, Q., Lin, X., Jin, Z., Wang, L., Chen, G., Xiu, F., Liu, W., Zhang, C. & Ma, G. (2019). Ultrafast photocarrier dynamics in a 3D Dirac semimetal Cd3As2 film studied with terahertz spectroscopy. Applied Physics Letters, 114 (22), 221102-1-221102-5.

Scopus Eid


  • 2-s2.0-85066837651

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers1/2868

Start Page


  • 221102-1

End Page


  • 221102-5

Volume


  • 114

Issue


  • 22

Place Of Publication


  • United States