Abstract
This paper describes control of the rate constant for near-infrared excitonic energy transfer (EnT) within soluble aqueous assemblies of PbS quantum dots, cross-linked by Zn2+, by changing the length of the mercapto-alkanoic acid (MAA) that serves as the cross-linking ligand. Sequestration of Zn2+ by a chelating agent or zinc hydroxide species results in deaggregation of the assemblies with EnT turned "off". Upon decreasing the number of methylene groups in MAAs from 16 to 3, the interparticle separation decreases from 5.8 nm to 3.7 nm and the average observed EnT rate increases from ∼(150 ns)-1 to ∼(2 ns)-1. A master equation translates intrinsic (single-donor-single-acceptor) EnT rate constants predicted for each ligand length using Förster theory to observed average rate constants. For interparticle distances greater than ∼4 nm, the point dipole approximation (PDA) implementation of Förster theory agrees with experimentally measured rates. At shorter interparticle distances, the PDA drastically underestimates the observed EnT rate. The prediction of the rates of these short-distance EnT processes is improved by ∼20% by replacing the PDA with a transition density cube calculation of the interparticle Coulombic coupling.
| Original language | English |
|---|---|
| Pages (from-to) | 5041-5050 |
| Number of pages | 10 |
| Journal | ACS Nano |
| Volume | 11 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 23 2017 |
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Keywords
- cross-linking
- energy transfer
- Förster theory
- near-infrared
- quantum dot assemblies
- transition density cube method
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Distance-Dependence of Interparticle Energy Transfer in the Near-Infrared within Electrostatic Assemblies of PbS Quantum Dots. / Kodaimati, Mohamad S.; Wang, Chen; Chapman, Craig; Schatz, George C; Weiss, Emily A.
In: ACS Nano, Vol. 11, No. 5, 23.05.2017, p. 5041-5050.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Distance-Dependence of Interparticle Energy Transfer in the Near-Infrared within Electrostatic Assemblies of PbS Quantum Dots
AU - Kodaimati, Mohamad S.
AU - Wang, Chen
AU - Chapman, Craig
AU - Schatz, George C
AU - Weiss, Emily A
PY - 2017/5/23
Y1 - 2017/5/23
N2 - This paper describes control of the rate constant for near-infrared excitonic energy transfer (EnT) within soluble aqueous assemblies of PbS quantum dots, cross-linked by Zn2+, by changing the length of the mercapto-alkanoic acid (MAA) that serves as the cross-linking ligand. Sequestration of Zn2+ by a chelating agent or zinc hydroxide species results in deaggregation of the assemblies with EnT turned "off". Upon decreasing the number of methylene groups in MAAs from 16 to 3, the interparticle separation decreases from 5.8 nm to 3.7 nm and the average observed EnT rate increases from ∼(150 ns)-1 to ∼(2 ns)-1. A master equation translates intrinsic (single-donor-single-acceptor) EnT rate constants predicted for each ligand length using Förster theory to observed average rate constants. For interparticle distances greater than ∼4 nm, the point dipole approximation (PDA) implementation of Förster theory agrees with experimentally measured rates. At shorter interparticle distances, the PDA drastically underestimates the observed EnT rate. The prediction of the rates of these short-distance EnT processes is improved by ∼20% by replacing the PDA with a transition density cube calculation of the interparticle Coulombic coupling.
AB - This paper describes control of the rate constant for near-infrared excitonic energy transfer (EnT) within soluble aqueous assemblies of PbS quantum dots, cross-linked by Zn2+, by changing the length of the mercapto-alkanoic acid (MAA) that serves as the cross-linking ligand. Sequestration of Zn2+ by a chelating agent or zinc hydroxide species results in deaggregation of the assemblies with EnT turned "off". Upon decreasing the number of methylene groups in MAAs from 16 to 3, the interparticle separation decreases from 5.8 nm to 3.7 nm and the average observed EnT rate increases from ∼(150 ns)-1 to ∼(2 ns)-1. A master equation translates intrinsic (single-donor-single-acceptor) EnT rate constants predicted for each ligand length using Förster theory to observed average rate constants. For interparticle distances greater than ∼4 nm, the point dipole approximation (PDA) implementation of Förster theory agrees with experimentally measured rates. At shorter interparticle distances, the PDA drastically underestimates the observed EnT rate. The prediction of the rates of these short-distance EnT processes is improved by ∼20% by replacing the PDA with a transition density cube calculation of the interparticle Coulombic coupling.
KW - cross-linking
KW - energy transfer
KW - Förster theory
KW - near-infrared
KW - quantum dot assemblies
KW - transition density cube method
UR - http://www.scopus.com/inward/record.url?scp=85019886133&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85019886133&partnerID=8YFLogxK
U2 - 10.1021/acsnano.7b01778
DO - 10.1021/acsnano.7b01778
M3 - Article
C2 - 28398717
AN - SCOPUS:85019886133
VL - 11
SP - 5041
EP - 5050
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 5
ER -