Unique Luminescent Properties of Composition-/Size-Selected Aqueous Ag-In-S and Core/Shell Ag-In-S/ZnS Quantum Dots

2020 ◽  
pp. 67-122 ◽  
Author(s):  
Oleksandr Stroyuk ◽  
Oleksandra Raievska ◽  
Dietrich R. T. Zahn
Keyword(s):  
Quantum Dots ◽  
Luminescent Properties ◽  
Core Shell

SYNTHESIS AND PHOTOLUMINESCENCE OF WATER-SOLUBLE ZnS:Mn2+/ZnS QUANTUM DOTS BY NUCLEATION DOPING STRATEGY

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 75-79 ◽  
Author(s):  
ZHANGSEN YU ◽  
XIYING MA
Keyword(s):  
Quantum Dots ◽  
Solution Structure ◽  
Thioglycolic Acid ◽  
Luminescent Properties ◽  
Fluorescent Labeling ◽  
Water Soluble ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions

We report the synthesis of luminescent-doped core/shell quantum dots (QDs) of water-soluble manganese-doped zinc sulfide (ZnS:Mn2+/ZnS) . QDs of ZnS:Mn2+/ZnS were prepared by nucleation doping strategy, with thioglycolic acid (TGA) as stabilizer in aqueous solution. Structure and optical properties of the ZnS:Mn2+/ZnS core/shell quantum dots were characterized by X-ray diffraction and photoluminescence emission spectroscopy. The influence of the synthesis conditions on the luminescent properties of ZnS:Mn2+/ZnS QDs is discussed. Different Mn2+ concentrations, ratios of the TGA/ (Zn+Mn) and thickness of the ZnS shell were used. Results showed that the ZnS:Mn2+/ZnS QDs are water-soluble and have improved fluorescence properties. Therefore, Mn2+ -doped ZnS quantum dots could be potential candidates as fluorescent labeling agents in biology.

High-Temperature Synthesis of CdSe-Based Core/Shell, Core/Shell/Shell, and Core/Graded-Shell Nanoplatelets for Stable and Efficient Narrowband Emitters

2019 ◽  
Author(s):  
Aurelio A. Rossinelli ◽  
Henar Rojo ◽  
Aniket S. Mule ◽  
Marianne Aellen ◽  
Ario Cocina ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Temperature ◽  
Equilibrium Shape ◽  
Size Variation ◽  
Crystal Defects ◽  
Atomic Scale ◽  
Quantum Yields ◽  
Core Shell ◽  
Compositional Gradient ◽  
High Quality

<div>Colloidal semiconductor nanoplatelets exhibit exceptionally narrow photoluminescence spectra. This occurs because samples can be synthesized in which all nanoplatelets share the same atomic-scale thickness. As this dimension sets the emission wavelength, inhomogeneous linewidth broadening due to size variation, which is always present in samples of quasi-spherical nanocrystals (quantum dots), is essentially eliminated. Nanoplatelets thus offer improved, spectrally pure emitters for various applications. Unfortunately, due to their non-equilibrium shape, nanoplatelets also suffer from low photo-, chemical, and thermal stability, which limits their use. Moreover, their poor stability hampers the development of efficient synthesis protocols for adding high-quality protective inorganic shells, which are well known to improve the performance of quantum dots. <br></div><div>Herein, we report a general synthesis approach to highly emissive and stable core/shell nanoplatelets with various shell compositions, including CdSe/ZnS, CdSe/CdS/ZnS, CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S, and CdSe/ZnSe. Motivated by previous work on quantum dots, we find that slow, high-temperature growth of shells containing a compositional gradient reduces strain-induced crystal defects and minimizes the emission linewidth while maintaining good surface passivation and nanocrystal uniformity. Indeed, our best core/shell nanoplatelets (CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S) show photoluminescence quantum yields of 90% with linewidths as low as 56 meV (19.5 nm at 655 nm). To confirm the high quality of our different core/shell nanoplatelets for a specific application, we demonstrate their use as gain media in low-threshold ring lasers. More generally, the ability of our synthesis protocol to engineer high-quality shells can help further improve nanoplatelets for optoelectronic devices.</div>

Enhanced Photocurrent Generation in Proton‐Irradiated “Giant” CdSe/CdS Core/Shell Quantum Dots

2019 ◽  
Vol 29 (46) ◽  
pp. 1904501 ◽  
Author(s):  
Chao Wang ◽  
David Barba ◽  
Gurpreet S. Selopal ◽  
Haiguang Zhao ◽  
Jiabin Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Core Shell ◽  
Photocurrent Generation

Fabrication and luminescent properties of core-shell InGaN/GaN multiple quantum wells on GaN nanopillars

2012 ◽  
Vol 100 (26) ◽  
pp. 261103 ◽  
Author(s):  
J.-R. Chang ◽  
S.-P. Chang ◽  
Y.-J. Li ◽  
Y.-J. Cheng ◽  
K.-P. Sou ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Luminescent Properties ◽  
Multiple Quantum Wells ◽  
Core Shell ◽  
Multiple Quantum

Surface Organic Ligands-Passivated Quantum Dots: Toward High-Performance Light-Emitting Diodes with Long Lifetime

2021 ◽  
Author(s):  
Lishuang Wang ◽  
Ying Lv ◽  
Jie Lin ◽  
Jialong Zhao ◽  
Xingyuan Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Ligands ◽  
Colloidal Quantum Dots ◽  
Core Shell ◽  
Light Emitting ◽  
Long Lifetime

For quantum dots light-emitting diodes (QLEDs), typical colloidal quantum dots (QDs) are usually composed of a core/shell heterostructure which is covered with organic ligands as surface passivated materials to confine...

Single-charge transport through hybrid core–shell Au-ZnS quantum dots: a comprehensive analysis from a modified energy structure

Nanoscale ◽  
2021 ◽  
Author(s):  
Tuhin Shuvra Basu ◽  
Simon Diesch ◽  
Ryoma Hayakawa ◽  
Yutaka Wakayama ◽  
Elke Scheer
Keyword(s):  
Quantum Dots ◽  
Electronic Structure ◽  
Carrier Transport ◽  
Comprehensive Analysis ◽  
Energy Structure ◽  
Core Shell ◽  
Single Charge ◽  
Scanning Tunnelling Microscope ◽  
Single Carrier ◽  
Scanning Tunnelling

We examined the modified electronic structure and single-carrier transport of individual hybrid core–shell metal–semiconductor Au-ZnS quantum dots using a scanning tunnelling microscope.

Fabrication of hybrid Pd@Ag core-shell and fully alloyed bi-metallic AgPd NPs and SERS enhancement of Rhodamine 6G by a unique mixture approach with graphene quantum dots

2021 ◽  
Vol 548 ◽  
pp. 149252
Author(s):  
Sanchaya Pandit ◽  
Sundar Kunwar ◽  
Rakesh Kulkarni ◽  
Rutuja Mandavka ◽  
Shusen Lin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Rhodamine 6G ◽  
Graphene Quantum Dots ◽  
Core Shell ◽  
Sers Enhancement
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