Carrier relaxation of ZnCdSe/ZnSe quantum wells

Der Jun Jang*, Meng En Lee, Yung Hsien Chung, Chu Shou Yang, Wu-Ching Chou

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

The energy relaxations of Zn0.91Cd0.09Se multiquantum wells and epilayer structures were studied with an ultrafast timeresolved photoluminescence apparatus. The increase in the rise time of photoluminescence with decreasing photon energy and the redshift of the peak energy of time-resolved photoluminescence spectra with the delay time are attributed to the bandfilling effect and energy relaxation of hot carriers. The derived carrier temperature decreases rapidly within the first 10 ps after photoexcitation and at a much slower rate thereafter. The fast carrier cooling can be explained by the longitudinal optical (LO) phonon emissions by carriers through the Fröhlich interaction. The obtained effective scattering times of carrier and LO phonons are comparable to the theoretical prediction of 20 fs for multi-quantum well (MQW) of 20 nm well thickness and the epilayer. The slow carrier capture process may account for the long effective scattering time of 35 fs for the MQWs of 5 nm well thickness.

Original languageEnglish
Pages (from-to)7056-7059
Number of pages4
JournalJapanese Journal of Applied Physics
Volume47
Issue number9 PART 1
DOIs
StatePublished - 12 Sep 2008

Keywords

  • Carrier capture
  • Energy relaxation
  • Hot carrier
  • Optical phonon
  • Quantum well
  • ZnCdSe

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