Ultrafast carrier capture and relaxation in modulation-doped InAs quantum dots

Kien-Wen Sun*, A. Kechiantz, B. C. Lee, C. P. Lee

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

We report investigations on carrier capture and relaxation processes in undoped and modulation-doped InAsGaAs self-assembled quantum dots (QDs) by using time-resolved spectroscopy technique with a time resolution of ∼200 fs. We find that carrier capture and relaxation in the ground state of the charged QD are faster compared to the undoped dots even at an excitation level as low as 1× 1010 cm-2. It is attributed to the triggering of the vibrating polarization field induced by the presence of cold carriers in the doped dots. The rate of an electron been captured by a positively charged QD is also calculated based on our proposed model.

Original languageEnglish
Article number163117
JournalApplied Physics Letters
Volume88
Issue number16
DOIs
StatePublished - 17 Apr 2006

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