Advanced (1)H, (13)C, and (31)P solution and solid-state NMR studies combined with IR spectroscopy were used to probe, at the molecular scale, the composition and the surface chemistry of indium phosphide (InP) quantum dots (QDs) prepared via a non-coordinating solvent strategy. This nanomaterial can be described as a core-multishell object: an InP core, with a zinc blende bulk structure, is surrounded first by a partially oxidized surface shell, which is itself surrounded by an organic coating. This organic passivating layer is composed, in the first coordination sphere, of tightly bound palmitate ligands which display two different bonding modes. A second coordination sphere includes an unexpected dialkyl ketone and residual long-chain non-coordinating solvents (ODE and its isomers) which interact through weak intermolecular bonds with the alkyl chains of the carboxylate ligands. We show that this ketone is formed during the synthesis process via a decarboxylative coupling route and provides oxidative conditions which are responsible for the oxidation of the InP core surface. This phenomenon has a significant impact on the photoluminescence properties of the as-synthesized QDs and probably accounts for the failure of further growth of the InP core.
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http://dx.doi.org/10.1021/ja104673y | DOI Listing |
ACS Appl Mater Interfaces
December 2024
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China.
High-performance, environmentally friendly indium phosphide (InP)-based quantum dots (QDs) are urgently needed to meet the demands of rapidly evolving display and lighting technologies. By adopting the highly efficient and cost-effective one-pot method and utilizing aluminum isopropoxide (AIP) as the Al source, a series of Al-doped InP/(Al)ZnS QDs with emission maxima ranging from 480 to 627 nm were synthesized. The photoluminescence quantum yield (PLQY) of the blue, green, yellow, orange, and red QDs, with emission peaks at 480, 509, 560, 600, and 627 nm, reached 34%, 62%, 86%, 96%, and 85%, respectively.
View Article and Find Full Text PDFNano Lett
December 2024
Key Laboratory of Advanced Display and System Applications Education of Ministry, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
Indium phosphide (InP) quantum dots (QDs) are promising alternative heavy-metal CdSe QDs for light-emitting diode (LED) application. However, their highly reactive core surface is prone to oxidation, which reduces the photoluminescence quantum yield (PL QY) and impedes subsequent shell growth. Traditional etching methods using HF aqueous solution are problematic as water can induce reoxidation during or after etching.
View Article and Find Full Text PDFSmall Methods
December 2024
Division of Materials Science and Engineerin, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
The formation of core-shell quantum dots (QDs) with type-I band alignment results in surface passivation, ensuring the efficient confinement of excitons for light-emitting applications. In such cases, the atomic composition at the core-shell heterojunction significantly affects the optical, and electrical properties of the QDs. However, for InP cores, shell materials are limited to compositions consisting of II-VI group elements.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Institute of Biochemistry, Food Science and Nutrition. The Robert H. Smith Faculty of Agriculture, Food and Environment. The Hebrew University of Jerusalem. 229 Herzl Street, Rehovot 7610001, Israel.
Mammals withstand frequent and prolonged fasting periods due to hepatic production of glucose and ketone bodies. Because the fasting response is transcriptionally regulated, we asked whether enhancer dynamics impose a transcriptional program during recurrent fasting and whether this generates effects distinct from a single fasting bout. We found that mice undergoing alternate-day fasting (ADF) respond profoundly differently to a following fasting bout compared to mice first experiencing fasting.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Bioinformatics Group, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
Specialized or secondary metabolites are small molecules of biological origin, often showing potent biological activities with applications in agriculture, engineering and medicine. Usually, the biosynthesis of these natural products is governed by sets of co-regulated and physically clustered genes known as biosynthetic gene clusters (BGCs). To share information about BGCs in a standardized and machine-readable way, the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard and repository was initiated in 2015.
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