Exchange interaction in InAs nanocrystal quantum dots

U. Banin; J. C. Lee; A. A. Guzelian; A. V. Kadavanich; A. P. Alivisatos

doi:10.1006/spmi.1997.0504

Exchange interaction in InAs nanocrystal quantum dots

U. Banin^*, J. C. Lee, A. A. Guzelian, A. V. Kadavanich, A. P. Alivisatos

^*Corresponding author for this work

Institute of Chemistry

Research output: Contribution to journal › Article › peer-review

72 Scopus citations

Abstract

The near band-gap level structure in high-quality colloidal InAs nanocrystal quantum dots within the very strong confinement regime is investigated. Size-selective photoluminescence excitation and fluorescence line narrowing measurements reveal a size-dependent splitting between the absorbing and the emitting states. The splitting is assigned to the confinement-enhanced electron - hole exchange interaction. The size dependence of the splitting significantly deviates from the idealized 1/r³ scaling law for the exchange splitting. A model incorporating a finite barrier which allows for wavefunction leakage is introduced. The model reproduces the observed 1/r² dependence of the splitting and good agreement with the experimental data is obtained. The smaller barriers for embedded InAs dots grown by molecular-beam epitaxy, are predicted to result in smaller exchange splitting as compared with colloidal dots with a similar number of atoms.

Original language	English
Pages (from-to)	559-568
Number of pages	10
Journal	Superlattices and Microstructures
Volume	22
Issue number	4
DOIs	https://doi.org/10.1006/spmi.1997.0504
State	Published - Dec 1997

Bibliographical note

Funding Information:
Acknowledgements—U.B. thanks the Rothschild and Fulbright foundations for support. We thank Dr W. Jaskolski for assistance in the overlap calculations and Dr Al. L. Efros for helpful discussions. This work was supported by the U.S. National Science Foundation under contract number DMR-9505302.

Keywords

Exchange splitting
InAs
Quantum dots
Semiconductor nanocrystal

Access to Document

10.1006/spmi.1997.0504

Cite this

@article{50edaae6371c4ce29f193dce1e960086,

title = "Exchange interaction in InAs nanocrystal quantum dots",

abstract = "The near band-gap level structure in high-quality colloidal InAs nanocrystal quantum dots within the very strong confinement regime is investigated. Size-selective photoluminescence excitation and fluorescence line narrowing measurements reveal a size-dependent splitting between the absorbing and the emitting states. The splitting is assigned to the confinement-enhanced electron - hole exchange interaction. The size dependence of the splitting significantly deviates from the idealized 1/r3 scaling law for the exchange splitting. A model incorporating a finite barrier which allows for wavefunction leakage is introduced. The model reproduces the observed 1/r2 dependence of the splitting and good agreement with the experimental data is obtained. The smaller barriers for embedded InAs dots grown by molecular-beam epitaxy, are predicted to result in smaller exchange splitting as compared with colloidal dots with a similar number of atoms.",

keywords = "Exchange splitting, InAs, Quantum dots, Semiconductor nanocrystal",

author = "U. Banin and Lee, {J. C.} and Guzelian, {A. A.} and Kadavanich, {A. V.} and Alivisatos, {A. P.}",

note = "Funding Information: Acknowledgements—U.B. thanks the Rothschild and Fulbright foundations for support. We thank Dr W. Jaskolski for assistance in the overlap calculations and Dr Al. L. Efros for helpful discussions. This work was supported by the U.S. National Science Foundation under contract number DMR-9505302.",

year = "1997",

month = dec,

doi = "10.1006/spmi.1997.0504",

language = "אנגלית",

volume = "22",

pages = "559--568",

journal = "Superlattices and Microstructures",

issn = "0749-6036",

publisher = "Elsevier Ltd.",

number = "4",

}

TY - JOUR

T1 - Exchange interaction in InAs nanocrystal quantum dots

AU - Banin, U.

AU - Lee, J. C.

AU - Guzelian, A. A.

AU - Kadavanich, A. V.

AU - Alivisatos, A. P.

N1 - Funding Information: Acknowledgements—U.B. thanks the Rothschild and Fulbright foundations for support. We thank Dr W. Jaskolski for assistance in the overlap calculations and Dr Al. L. Efros for helpful discussions. This work was supported by the U.S. National Science Foundation under contract number DMR-9505302.

PY - 1997/12

Y1 - 1997/12

N2 - The near band-gap level structure in high-quality colloidal InAs nanocrystal quantum dots within the very strong confinement regime is investigated. Size-selective photoluminescence excitation and fluorescence line narrowing measurements reveal a size-dependent splitting between the absorbing and the emitting states. The splitting is assigned to the confinement-enhanced electron - hole exchange interaction. The size dependence of the splitting significantly deviates from the idealized 1/r3 scaling law for the exchange splitting. A model incorporating a finite barrier which allows for wavefunction leakage is introduced. The model reproduces the observed 1/r2 dependence of the splitting and good agreement with the experimental data is obtained. The smaller barriers for embedded InAs dots grown by molecular-beam epitaxy, are predicted to result in smaller exchange splitting as compared with colloidal dots with a similar number of atoms.

AB - The near band-gap level structure in high-quality colloidal InAs nanocrystal quantum dots within the very strong confinement regime is investigated. Size-selective photoluminescence excitation and fluorescence line narrowing measurements reveal a size-dependent splitting between the absorbing and the emitting states. The splitting is assigned to the confinement-enhanced electron - hole exchange interaction. The size dependence of the splitting significantly deviates from the idealized 1/r3 scaling law for the exchange splitting. A model incorporating a finite barrier which allows for wavefunction leakage is introduced. The model reproduces the observed 1/r2 dependence of the splitting and good agreement with the experimental data is obtained. The smaller barriers for embedded InAs dots grown by molecular-beam epitaxy, are predicted to result in smaller exchange splitting as compared with colloidal dots with a similar number of atoms.

KW - Exchange splitting

KW - InAs

KW - Quantum dots

KW - Semiconductor nanocrystal

UR - http://www.scopus.com/inward/record.url?scp=30244463883&partnerID=8YFLogxK

U2 - 10.1006/spmi.1997.0504

DO - 10.1006/spmi.1997.0504

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:30244463883

SN - 0749-6036

VL - 22

SP - 559

EP - 568

JO - Superlattices and Microstructures

JF - Superlattices and Microstructures

IS - 4

ER -

Exchange interaction in InAs nanocrystal quantum dots

Abstract

Bibliographical note

Keywords

Access to Document

Other files and links

Fingerprint

Cite this