Organic surfactant-controlled composition of the surfaces of CdSe quantum dots

Adam J. Morris-Cohen, Matthew T. Frederick, G. Daniel Lilly, Eric A. McArthur, Emily A Weiss

Research output: Contribution to journalArticle

85 Citations (Scopus)

Abstract

The ratio of Cd to Se (Cd/Se) within colloidal CdSe quantum dots (QDs) synthesized with 90% trioctylphosphine oxide (TOPO) as the coordinating solvent increases from 1.2:1 for QDs with radius R ≥ 3.3 nm to 6.5:1 for R = 1.9 nm, as measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The highest value of Cd/Se reported previously for CdSe QDs was 1.8:1. The dependence of Cd/Se on R fits a geometric model that describes the QDs as CdSe cores with Cd/Se = 1:1 encapsulated by a shell of Cd-organic complexes. Use of 99% TOPO as the coordinating solvent produces QDs with Cd/Se = 1:1 for all values of R, and use of 99% TOPO "doped" with n-octylphosphonic acid (OPA), an impurity in 90% TOPO, produces QDs with values of Cd/Se up to 1.5:1. These results imply that Cd enrichment of the QDs is driven by tight-binding Cd2+-alkylphosphonate complexes that stabilize the interface between the polar CdSe core and the organic medium.

Original languageEnglish
Pages (from-to)1078-1081
Number of pages4
JournalJournal of Physical Chemistry Letters
Volume1
Issue number7
DOIs
Publication statusPublished - Apr 1 2010

Fingerprint

Surface-Active Agents
Semiconductor quantum dots
Surface active agents
surfactants
quantum dots
Chemical analysis
Oxides
oxides
Atomic emission spectroscopy
Inductively coupled plasma
Impurities
impurities
acids
radii
Acids
trioctyl phosphine oxide
spectroscopy

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Organic surfactant-controlled composition of the surfaces of CdSe quantum dots. / Morris-Cohen, Adam J.; Frederick, Matthew T.; Lilly, G. Daniel; McArthur, Eric A.; Weiss, Emily A.

In: Journal of Physical Chemistry Letters, Vol. 1, No. 7, 01.04.2010, p. 1078-1081.

Research output: Contribution to journalArticle

Morris-Cohen, Adam J. ; Frederick, Matthew T. ; Lilly, G. Daniel ; McArthur, Eric A. ; Weiss, Emily A. / Organic surfactant-controlled composition of the surfaces of CdSe quantum dots. In: Journal of Physical Chemistry Letters. 2010 ; Vol. 1, No. 7. pp. 1078-1081.
@article{64bd3bfcaad448449d0bbbc54cd3cd3e,
title = "Organic surfactant-controlled composition of the surfaces of CdSe quantum dots",
abstract = "The ratio of Cd to Se (Cd/Se) within colloidal CdSe quantum dots (QDs) synthesized with 90{\%} trioctylphosphine oxide (TOPO) as the coordinating solvent increases from 1.2:1 for QDs with radius R ≥ 3.3 nm to 6.5:1 for R = 1.9 nm, as measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The highest value of Cd/Se reported previously for CdSe QDs was 1.8:1. The dependence of Cd/Se on R fits a geometric model that describes the QDs as CdSe cores with Cd/Se = 1:1 encapsulated by a shell of Cd-organic complexes. Use of 99{\%} TOPO as the coordinating solvent produces QDs with Cd/Se = 1:1 for all values of R, and use of 99{\%} TOPO {"}doped{"} with n-octylphosphonic acid (OPA), an impurity in 90{\%} TOPO, produces QDs with values of Cd/Se up to 1.5:1. These results imply that Cd enrichment of the QDs is driven by tight-binding Cd2+-alkylphosphonate complexes that stabilize the interface between the polar CdSe core and the organic medium.",
author = "Morris-Cohen, {Adam J.} and Frederick, {Matthew T.} and Lilly, {G. Daniel} and McArthur, {Eric A.} and Weiss, {Emily A}",
year = "2010",
month = "4",
day = "1",
doi = "10.1021/jz100224q",
language = "English",
volume = "1",
pages = "1078--1081",
journal = "Journal of Physical Chemistry Letters",
issn = "1948-7185",
publisher = "American Chemical Society",
number = "7",

}

TY - JOUR

T1 - Organic surfactant-controlled composition of the surfaces of CdSe quantum dots

AU - Morris-Cohen, Adam J.

AU - Frederick, Matthew T.

AU - Lilly, G. Daniel

AU - McArthur, Eric A.

AU - Weiss, Emily A

PY - 2010/4/1

Y1 - 2010/4/1

N2 - The ratio of Cd to Se (Cd/Se) within colloidal CdSe quantum dots (QDs) synthesized with 90% trioctylphosphine oxide (TOPO) as the coordinating solvent increases from 1.2:1 for QDs with radius R ≥ 3.3 nm to 6.5:1 for R = 1.9 nm, as measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The highest value of Cd/Se reported previously for CdSe QDs was 1.8:1. The dependence of Cd/Se on R fits a geometric model that describes the QDs as CdSe cores with Cd/Se = 1:1 encapsulated by a shell of Cd-organic complexes. Use of 99% TOPO as the coordinating solvent produces QDs with Cd/Se = 1:1 for all values of R, and use of 99% TOPO "doped" with n-octylphosphonic acid (OPA), an impurity in 90% TOPO, produces QDs with values of Cd/Se up to 1.5:1. These results imply that Cd enrichment of the QDs is driven by tight-binding Cd2+-alkylphosphonate complexes that stabilize the interface between the polar CdSe core and the organic medium.

AB - The ratio of Cd to Se (Cd/Se) within colloidal CdSe quantum dots (QDs) synthesized with 90% trioctylphosphine oxide (TOPO) as the coordinating solvent increases from 1.2:1 for QDs with radius R ≥ 3.3 nm to 6.5:1 for R = 1.9 nm, as measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The highest value of Cd/Se reported previously for CdSe QDs was 1.8:1. The dependence of Cd/Se on R fits a geometric model that describes the QDs as CdSe cores with Cd/Se = 1:1 encapsulated by a shell of Cd-organic complexes. Use of 99% TOPO as the coordinating solvent produces QDs with Cd/Se = 1:1 for all values of R, and use of 99% TOPO "doped" with n-octylphosphonic acid (OPA), an impurity in 90% TOPO, produces QDs with values of Cd/Se up to 1.5:1. These results imply that Cd enrichment of the QDs is driven by tight-binding Cd2+-alkylphosphonate complexes that stabilize the interface between the polar CdSe core and the organic medium.

UR - http://www.scopus.com/inward/record.url?scp=77950573375&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77950573375&partnerID=8YFLogxK

U2 - 10.1021/jz100224q

DO - 10.1021/jz100224q

M3 - Article

VL - 1

SP - 1078

EP - 1081

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

SN - 1948-7185

IS - 7

ER -