TY  - GEN
A1  - Heyne, Benjamin
A1  - Arlt, Kristin
A1  - Geßner, André
A1  - Richter, Alexander F.
A1  - Döblinger, Markus
A1  - Feldmann, Jochen
A1  - Taubert, Andreas
A1  - Wedel, Armin
T1  - Mixed Mercaptocarboxylic Acid Shells Provide Stable Dispersions of InPZnS/ZnSe/ZnS Multishell Quantum Dots in Aqueous Media
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Highly luminescent indium phosphide zinc sulfide (InPZnS) quantum dots (QDs), with zinc selenide/zinc sulfide (ZnSe/ZnS) shells, were synthesized. The QDs were modified via a post-synthetic ligand exchange reaction with 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) in different MPA:MUA ratios, making this study the first investigation into the effects of mixed ligand shells on InPZnS QDs. Moreover, this article also describes an optimized method for the correlation of the QD size vs. optical absorption of the QDs. Upon ligand exchange, the QDs can be dispersed in water. Longer ligands (MUA) provide more stable dispersions than short-chain ligands. Thicker ZnSe/ZnS shells provide a better photoluminescence quantum yield (PLQY) and higher emission stability upon ligand exchange. Both the ligand exchange and the optical properties are highly reproducible between different QD batches. Before dialysis, QDs with a ZnS shell thickness of ~4.9 monolayers (ML), stabilized with a mixed MPA:MUA (mixing ratio of 1:10), showed the highest PLQY, at ~45%. After dialysis, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with a mixed MPA:MUA and a ratio of 1:10 and 1:100, showed the highest PLQYs, of ~41%. The dispersions were stable up to 44 days at ambient conditions and in the dark. After 44 days, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with only MUA, showed the highest PLQY, of ~34%.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1026 
KW  - quantum dots
KW  - cadmium-free
KW  - Cd-free
KW  - InP
KW  - InPZnS
KW  - multishell
KW  - mercaptocarboxylic acids
KW  - 3-mercaptopropionic acid
KW  - 11-mercaptoundecanoic acid
KW  - phase transfer
KW  - ligand exchange
KW  - aqueous dispersion
KW  - QDs
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-486032
SN  - 1866-8372
IS  - 1026
ER  - 
TY  - JOUR
A1  - Heyne, Benjamin
A1  - Arlt, Kristin
A1  - Geßner, André
A1  - Richter, Alexander F.
A1  - Döblinger, Markus
A1  - Feldmann, Jochen
A1  - Taubert, Andreas
A1  - Wedel, Armin
T1  - Mixed Mercaptocarboxylic Acid Shells Provide Stable Dispersions of InPZnS/ZnSe/ZnS Multishell Quantum Dots in Aqueous Media
JF  - Nanomaterials
N2  - Highly luminescent indium phosphide zinc sulfide (InPZnS) quantum dots (QDs), with zinc selenide/zinc sulfide (ZnSe/ZnS) shells, were synthesized. The QDs were modified via a post-synthetic ligand exchange reaction with 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) in different MPA:MUA ratios, making this study the first investigation into the effects of mixed ligand shells on InPZnS QDs. Moreover, this article also describes an optimized method for the correlation of the QD size vs. optical absorption of the QDs. Upon ligand exchange, the QDs can be dispersed in water. Longer ligands (MUA) provide more stable dispersions than short-chain ligands. Thicker ZnSe/ZnS shells provide a better photoluminescence quantum yield (PLQY) and higher emission stability upon ligand exchange. Both the ligand exchange and the optical properties are highly reproducible between different QD batches. Before dialysis, QDs with a ZnS shell thickness of ~4.9 monolayers (ML), stabilized with a mixed MPA:MUA (mixing ratio of 1:10), showed the highest PLQY, at ~45%. After dialysis, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with a mixed MPA:MUA and a ratio of 1:10 and 1:100, showed the highest PLQYs, of ~41%. The dispersions were stable up to 44 days at ambient conditions and in the dark. After 44 days, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with only MUA, showed the highest PLQY, of ~34%.
KW  - quantum dots
KW  - cadmium-free
KW  - Cd-free
KW  - InP
KW  - InPZnS
KW  - multishell
KW  - mercaptocarboxylic acids
KW  - 3-mercaptopropionic acid
KW  - 11-mercaptoundecanoic acid
KW  - phase transfer
KW  - ligand exchange
KW  - aqueous dispersion
KW  - QDs
Y1  - 2020
U6  - https://doi.org/10.3390/nano10091858
SN  - 2079-4991
VL  - 10
IS  - 9
PB  - MDPI
CY  - Basel
ER  -