TY - JOUR
T1 - Thiol-Ligand-Catalyzed Quenching and Etching in Mixtures of Colloidal Quantum Dots and Silver Nanoparticles
AU - Lee, Jae Seung
AU - Kim, Hyungki
AU - Algar, W. Russ
N1 - Funding Information:
W.R.A. and H.K. acknowledge support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). W.R.A. is grateful for a Canada Research Chair (Tier 2), a Michael Smith Foundation for Health Research Scholar Award, and an Alfred P. Sloan Fellowship. H.K. is grateful for a NSERC Canada Graduate Scholarship and a UBC 4YF award. J.S.L. acknowledges support from the NRF funded by the Korean government, MSIP (NRF-2015M3A9D7031015, NRF-2016R1A5A1010148, and NRF-2015R1C1A1A01053865). The authors appreciate helpful discussion with Dan Bizzotto and thank Saeid Kamal, Melissa Massey, Eleonora Petryayeva, and Ken Wong for their experimental assistance. The ESI-MS spectra were obtained using the facilities of the Korea Basic Science Institute (KBSI; Seoul, Republic of Korea). Transient absorption and PL decay measurements were done in the Laboratory for Advanced Spectroscopy and Imaging Research (LASIR) at UBC. XPS measurements were done at the Interfacial Analysis & Reactivity Laboratory (IARL) at UBC.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/12/28
Y1 - 2017/12/28
N2 - Plasmonic nanostructures have the potential to enhance the emissive properties of semiconductor quantum dots (QDs). Although gold nanoparticles have been widely used for this purpose, other metals, such as silver, are also of interest and have more desirable plasmonic properties; however, silver nanoparticles suffer from chemical instability that gold nanoparticles do not. We find that this instability has the potential to limit the integration of silver nanoparticles (AgNPs) with QDs. Specifically, the common selection of thiol ligands for colloidal stabilization of QDs is incompatible with AgNPs, whether silver nanospheres or silver nanoplates. Equilibrium desorption of thiol ligands from QDs drives a pseudocatalytic process wherein the AgNPs are etched to produce silver(I)-ligand complexes, which then undergo cation exchange reactions at the QD leading to quenching of its photoluminescence (PL) through the introduction of long-lived trap states. We characterize this process through a combination of morphological, chemical, and steady-state and time-resolved spectroscopic measurements. The latter include extinction and absorption, PL emission intensity and lifetime, and transient absorption. Importantly, the etching and quenching process is avoided with QDs that are coated with an amphiphilic polymer instead of thiol ligands.
AB - Plasmonic nanostructures have the potential to enhance the emissive properties of semiconductor quantum dots (QDs). Although gold nanoparticles have been widely used for this purpose, other metals, such as silver, are also of interest and have more desirable plasmonic properties; however, silver nanoparticles suffer from chemical instability that gold nanoparticles do not. We find that this instability has the potential to limit the integration of silver nanoparticles (AgNPs) with QDs. Specifically, the common selection of thiol ligands for colloidal stabilization of QDs is incompatible with AgNPs, whether silver nanospheres or silver nanoplates. Equilibrium desorption of thiol ligands from QDs drives a pseudocatalytic process wherein the AgNPs are etched to produce silver(I)-ligand complexes, which then undergo cation exchange reactions at the QD leading to quenching of its photoluminescence (PL) through the introduction of long-lived trap states. We characterize this process through a combination of morphological, chemical, and steady-state and time-resolved spectroscopic measurements. The latter include extinction and absorption, PL emission intensity and lifetime, and transient absorption. Importantly, the etching and quenching process is avoided with QDs that are coated with an amphiphilic polymer instead of thiol ligands.
UR - http://www.scopus.com/inward/record.url?scp=85040128883&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.7b10381
DO - 10.1021/acs.jpcc.7b10381
M3 - Article
AN - SCOPUS:85040128883
SN - 1932-7447
VL - 121
SP - 28566
EP - 28575
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 51
ER -