Theoretical and experimental investigation of electronic structure and relaxation of colloidal nanocrystalline indium phosphide quantum dots

Randy J. Ellingson, Jeff L. Blackburn, Jovan Nedeljkovic, Gary Rumbles, Marcus Jones, Huaxiang Fu, Arthur J. Nozik

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25 Citations (Scopus)

Abstract

We present results of theoretical studies of the electronic structure, and experimental studies of electronic relaxation dynamics, for colloidally synthesized InP quantum dots (QD's). Detailed theoretical calculations of the electronic structure of a 41.8 Å diameter InP QD, based on an atomistic pseudopotiential approach, are presented and discussed in the context of experimental measurements. Using femtosecond transient absorption (TA) spectroscopy, we find that the rate of relaxation of photogenerated excitons to the lowest-energy exciton level varies depending upon excitation energy and surface chemistry. Etching the QD's passivates surface electron traps and yields enhanced carrier cooling, which we ascribe to improved confinement of charge carriers to the QD core. When exciting near or slightly above the first exciton state, we observe a subpicosecond decay of the band edge TA bleach signal which we attribute to a thermalization process. We also present size-selective transient absorption measurements providing experimental evidence which confirms the existence of two s-like exciton states spaced by ∼100 meV.

Original languageEnglish
Article number075308
Pages (from-to)753081-753088
Number of pages8
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume67
Issue number7
Publication statusPublished - Feb 15 2003

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Indium phosphide
indium phosphides
Excitons
Semiconductor quantum dots
Electronic structure
quantum dots
excitons
electronic structure
Plasma confinement
Electron traps
Excitation energy
Surface chemistry
Charge carriers
Absorption spectroscopy
charge carriers
Etching
absorption spectroscopy
etching
traps
chemistry

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Theoretical and experimental investigation of electronic structure and relaxation of colloidal nanocrystalline indium phosphide quantum dots. / Ellingson, Randy J.; Blackburn, Jeff L.; Nedeljkovic, Jovan; Rumbles, Gary; Jones, Marcus; Fu, Huaxiang; Nozik, Arthur J.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 67, No. 7, 075308, 15.02.2003, p. 753081-753088.

Research output: Contribution to journalArticle

Ellingson, Randy J. ; Blackburn, Jeff L. ; Nedeljkovic, Jovan ; Rumbles, Gary ; Jones, Marcus ; Fu, Huaxiang ; Nozik, Arthur J. / Theoretical and experimental investigation of electronic structure and relaxation of colloidal nanocrystalline indium phosphide quantum dots. In: Physical Review B - Condensed Matter and Materials Physics. 2003 ; Vol. 67, No. 7. pp. 753081-753088.
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