Effect of electronic structure on carrier multiplication efficiency: Comparative study of PbSe and CdSe nanocrystals

Richard D. Schaller, Melissa A. Petruska, Victor I. Klimov*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

256 Scopus citations

Abstract

Recently, we demonstrated that PbSe nanocrystal quantum dots can efficiently produce multiple electron-hole pairs (excitons) in response to a single absorbed photon. To address the generality of this carrier-multiplication phenomenon to other materials, we perform a comparative study of multiexciton generation in PbSe and CdSe nanocrystals that have distinctly different electronic structures. We find that both materials exhibit high-efficiency carrier multiplication and the activation threshold is lower in CdSe nanocrystals than in PbSe nanocrystals (∼2.5 vs ∼2.9 energy gaps). Furthermore, the efficiencies of multiexciton generation are nearly identical for both materials despite a vast difference in both energy structures and carrier relaxation behaviors, strongly suggesting that this phenomenon is general to quantum-confined semiconductor nanocrystals.

Original languageEnglish (US)
Article number253102
Pages (from-to)1-3
Number of pages3
JournalApplied Physics Letters
Volume87
Issue number25
DOIs
StatePublished - 2005

Funding

This work was supported by the Chemical Sciences, Biosciences and Geosciences Division of the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy and Los Alamos LDRD funds. R.D.S. is supported by a Frederick Reines Fellowship.

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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