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Ligand Shell Structure in Lead Sulfide–Oleic Acid Colloidal Quantum Dots Revealed by Small-Angle Scattering

Authors :
Weir, Michael P.
Toolan, Daniel T. W.
Kilbride, Rachel C.
Penfold, Nicholas J. W.
Washington, Adam L.
King, Stephen M.
Xiao, James
Zhang, Zhilong
Gray, Victor
Dowland, Simon
Winkel, Jurjen
Greenham, Neil C.
Friend, Richard H.
Rao, Akshay
Ryan, Anthony J.
Jones, Richard A. L.
Weir, Michael P.
Toolan, Daniel T. W.
Kilbride, Rachel C.
Penfold, Nicholas J. W.
Washington, Adam L.
King, Stephen M.
Xiao, James
Zhang, Zhilong
Gray, Victor
Dowland, Simon
Winkel, Jurjen
Greenham, Neil C.
Friend, Richard H.
Rao, Akshay
Ryan, Anthony J.
Jones, Richard A. L.
Publication Year :
2019

Abstract

Nanocrystal quantum dots are generally coated with an organic ligand layer. These layers are a necessary consequence of their chemical synthesis, and in addition they play a key role in controlling the optical and electronic properties of the system. Here we describe a method for quantitative measurement of the ligand layer in 3 nm diameter lead sulfide–oleic acid quantum dots. Complementary small-angle X-ray and neutron scattering (SAXS and SANS) studies give a complete and quantitative picture of the nanoparticle structure. We find greater-than-monolayer coverage of oleic acid and a significant proportion of ligand remaining in solution, and we demonstrate reversible thermal cycling of the oleic acid coverage. We outline the effectiveness of simple purification procedures with applications in preparing dots for efficient ligand exchange. Our method is transferrable to a wide range of colloidal nanocrystals and ligand chemistries, providing the quantitative means to enable the rational design of ligand-exchange procedures.

Details

Database :
OAIster
Notes :
English
Publication Type :
Electronic Resource
Accession number :
edsoai.on1312843731
Document Type :
Electronic Resource
Full Text :
https://doi.org/10.1021.acs.jpclett.9b01008