scholarly journals Compact high-quality CdSe–CdS core–shell nanocrystals with narrow emission linewidths and suppressed blinking

2013 ◽  
Vol 12 (5) ◽  
pp. 445-451 ◽  
Author(s):  
Ou Chen ◽  
Jing Zhao ◽  
Vikash P. Chauhan ◽  
Jian Cui ◽  
Cliff Wong ◽  
...  
Keyword(s):  
Core Shell ◽  
High Quality ◽  
Narrow Emission

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>

scholarly journals Epitaxial Growth of Ordered In-Plane Si and Ge Nanowires on Si (001)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 788
Author(s):  
Jian-Huan Wang ◽  
Ting Wang ◽  
Jian-Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Core Shell ◽  
High Quality ◽  
Quantum Devices ◽  
Wafer Scale ◽  
Transmission Electron ◽  
Controllable Growth

Controllable growth of wafer-scale in-plane nanowires (NWs) is a prerequisite for achieving addressable and scalable NW-based quantum devices. Here, by introducing molecular beam epitaxy on patterned Si structures, we demonstrate the wafer-scale epitaxial growth of site-controlled in-plane Si, SiGe, and Ge/Si core/shell NW arrays on Si (001) substrate. The epitaxially grown Si, SiGe, and Ge/Si core/shell NW are highly homogeneous with well-defined facets. Suspended Si NWs with four {111} facets and a side width of about 25 nm are observed. Characterizations including high resolution transmission electron microscopy (HRTEM) confirm the high quality of these epitaxial NWs.

Green and facile synthesis of high-quality water-soluble Ag-In-S/ZnS core/shell quantum dots with obvious bandgap and sub-bandgap excitations

2018 ◽  
Vol 753 ◽  
pp. 364-370 ◽  
Author(s):  
Yanyan Chen ◽  
Qiang Wang ◽  
Tianyong Zha ◽  
Jigang Min ◽  
Jingying Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Water Soluble ◽  
Core Shell ◽  
Facile Synthesis ◽  
High Quality ◽  
Quality Water

scholarly journals Highly qualified InP based QDs through a temperature controlled ZnSe shell coating process and their DFT calculations

2020 ◽  
Vol 2 (12) ◽  
pp. 5615-5622
Author(s):  
Haewoon Seo ◽  
Ju Hyun Park ◽  
O.-Hoon Kwon ◽  
O.Pil Kwon ◽  
Sang Kyu Kwak ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Core Shell ◽  
Coating Process ◽  
Regular Tetrahedron ◽  
Highly Qualified ◽  
Temperature Controlled ◽  
Coating Temperature ◽  
Narrow Emission

In the InP/ZnSe core/shell QD formation, the higher shell coating temperature resulted in regular tetrahedron shape and narrow emission FWHM.

One-pot synthesis of ultrasmall β-NaGdF4 nanoparticles with enhanced upconversion luminescence

2019 ◽  
Vol 7 (29) ◽  
pp. 8898-8904 ◽  
Author(s):  
Chunyan Cheng ◽  
Yueshan Xu ◽  
Songtao Liu ◽  
Yuanyuan Liu ◽  
Xian Wang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Upconversion Luminescence ◽  
Core Shell ◽  
High Quantum Yield ◽  
High Quality ◽  
Shell Nanoparticles ◽  
One Pot ◽  
High Quantum ◽  
One Pot Synthesis ◽  
Core Shell Nanoparticles

High quality β-NaGdYF4:Yb/Er and high quantum yield β-NaGdF4:Yb/Er@β-NaYF4 core shell nanoparticles were synthesized.

One-Pot Fabrication of High-Quality InP/ZnS (Core/Shell) Quantum Dots and Their Application to Cellular Imaging

ChemPhysChem ◽  
2009 ◽  
Vol 10 (9-10) ◽  
pp. 1466-1470 ◽  
Author(s):  
Sahid Hussain ◽  
Nayoun Won ◽  
Jutaek Nam ◽  
Jiwon Bang ◽  
Hyokyun Chung ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cellular Imaging ◽  
Core Shell ◽  
High Quality ◽  
One Pot

scholarly journals Quantum Dots and Applications

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 897
Author(s):  
Chang-Yeol Han ◽  
Hyun-Sik Kim ◽  
Heesun Yang
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Band Gap ◽  
Light Emitting Diodes ◽  
Photovoltaic Cells ◽  
Core Shell ◽  
Special Issue ◽  
High Quality ◽  
Light Emitting ◽  
Size Dependent

It is the unique size-dependent band gap of quantum dots (QDs) that makes them so special in various applications. They have attracted great interest, especially in optoelectronic fields such as light emitting diodes and photovoltaic cells, because their photoluminescent characteristics can be significantly improved via optimization of the processes by which they are synthesized. Control of their core/shell heterostructures is especially important and advantageous. However, a few challenges remain to be overcome before QD-based devices can completely replace current optoelectronic technology. This Special Issue provides detailed guides for synthesis of high-quality QDs and their applications. In terms of fabricating devices, tailoring optical properties of QDs and engineering defects in QD-related interfaces for higher performance remain important issues to be addressed.

Macroscopic assembly style of catalysts significantly determining their efficiency for converting CO2 to gasoline

2019 ◽  
Vol 9 (19) ◽  
pp. 5401-5412 ◽  
Author(s):  
Xiaoxing Wang ◽  
Guohui Yang ◽  
Junfeng Zhang ◽  
Faen Song ◽  
Yingquan Wu ◽  
...  
Keyword(s):  
Core Shell ◽  
High Quality ◽  
Efficient Conversion

Efficient conversion of CO2 into high-quality gasoline is realized over a Fe–Zn–Zr and HZSM-5 core–shell catalyst.

Core-Shell Structured Fe3O4/PPy Microspheres with High Magnetization for Purification of Plasmid DNA

2013 ◽  
Vol 716 ◽  
pp. 314-319 ◽  
Author(s):  
Hai Hui Jiang ◽  
Yan Zhou ◽  
Xiao Yun Han ◽  
Xin Cheng Chen ◽  
Yun Hua Hou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Delivery ◽  
Plasmid Dna ◽  
Magnetic Particles ◽  
Interfacial Polymerization ◽  
Core Shell ◽  
Magnetic Composite ◽  
Amino Group ◽  
High Quality ◽  
E Coli

Amino group-functionalized magnetic particles have wide applications in enzyme immobilization, DNA extraction, drug delivery, water purification, catalysis, and sensor. In this paper, Fe3O4/PPy microspheres with a well-defined coreshell structure have been prepared through an interfacial polymerization approach without surfactant. The magnetic composite spheres were characterized with XRD, FTIR, SEM, TEM, and magnetometry techniques, and further tested as the adsorbent to isolate plasmid DNA from Escherichia coli (E. coli) DH5α cells. The magnetic separation yields high-quality plasmid DNA in satisfying productivity as compared to the conventional phenolchloroform extraction.

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