Journal article
Excited-state dynamics and carrier capture in InGaAs/GaAs quantum dots
Applied physics letters, Vol.79(20), pp.3320-3322
11/12/2001
DOI: 10.1063/1.1418035
Abstract
Subpicosecond time-resolved photoluminescence upconversion is used to measure the 12 K first-excited-state dynamics in large InGaAs/GaAs self-assembled quantum dots designed for 1.3 μm diode lasers. A comparison with the ground-state dynamics suggests that energy relaxation occurs in a cascade through the multiple discrete levels with an average interlevel relaxation time of ∼250 fs. Excited-state emission is observed from two distinct populations. Due to the ultrafast relaxation from the excited state to the ground state in dots containing only a single exciton, the excited-state emission is dominated by the fraction of dots that capture more than one electron-hole pair. In this case, state filling in the ground state blocks the ultrafast relaxation channel, thereby enhancing the excited-state emission. While state filling and a random capture process dictate the primary features of the excited-state emission, at low excitation levels we find that the rise time of emission from the excited state is influenced by the much denser population of singly occupied dots. © 2001 American Institute of Physics.
Details
- Title: Subtitle
- Excited-state dynamics and carrier capture in InGaAs/GaAs quantum dots
- Creators
- L. Zhang - University of IowaThomas F. Boggess - University of IowaK. Gundogdu - University of IowaMichael E. Flatté - University of IowaD. G. Deppe - The University of Texas at AustinC. Cao - The University of Texas at AustinO. B. Shchekin - The University of Texas at Austin
- Resource Type
- Journal article
- Publication Details
- Applied physics letters, Vol.79(20), pp.3320-3322
- DOI
- 10.1063/1.1418035
- ISSN
- 0003-6951
- eISSN
- 1077-3118
- Language
- English
- Date published
- 11/12/2001
- Academic Unit
- Physics and Astronomy; Electrical and Computer Engineering
- Record Identifier
- 9984428792402771
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