Stability Investigation of CuInS2 based heavy-metal free nanocrystals

2011 ◽  
Vol 1316 ◽  
Author(s):  
Chuang Xie ◽  
Yu Zhang ◽  
Andrew Y. Wang ◽  
William W. Yu ◽  
Jingkang Wang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Uv Irradiation ◽  
Half Life ◽  
Ambient Condition ◽  
Core Shell ◽  
High Quality ◽  
Metal Free ◽  
Stability Investigation ◽  
Biomedical Fields

ABSTRACTIn the present work the photostability of high-quality CuInS2 based nanocrystals (Zn-Cu-In-S/ZnSe/ZnS and CuInS2/ZnS core/shell nanocrystals) of different sizes and concentrations were investigated at ambient condition both under UV irradiation and in the darkness. The photostability of commercial CdSe/ZnS core/shell nanocrystals were used as reference to compare to that of CuInS2 based nanocrystals. The half-life times of the CuInS2 base nanocrystals are 2-8 times that of the reference which indicates the CuInS2 base NCs we obtained in the present work are very stable, reliable and competent for the application in biomedical fields.

Near-Infrared, Heavy Metal-Free Colloidal “Giant” Core/Shell Quantum Dots

2017 ◽  
Vol 8 (2) ◽  
pp. 1701432 ◽  
Author(s):  
Xin Tong ◽  
Xiang-Tian Kong ◽  
Yufeng Zhou ◽  
Fabiola Navarro-Pardo ◽  
Gurpreet Singh Selopal ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Quantum Dots ◽  
Near Infrared ◽  
Core Shell ◽  
Metal Free

scholarly journals Green Synthesis of InP/ZnS Core/Shell Quantum Dots for Application in Heavy-Metal-Free Light-Emitting Diodes

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Tsung-Rong Kuo ◽  
Shih-Ting Hung ◽  
Yen-Ting Lin ◽  
Tzu-Lin Chou ◽  
Ming-Cheng Kuo ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Quantum Dots ◽  
Green Synthesis ◽  
Light Emitting Diodes ◽  
Core Shell ◽  
Light Emitting ◽  
Metal Free

scholarly journals Quantum Dots: Near-Infrared, Heavy Metal-Free Colloidal “Giant” Core/Shell Quantum Dots (Adv. Energy Mater. 2/2018)

2018 ◽  
Vol 8 (2) ◽  
pp. 1870010 ◽  
Author(s):  
Xin Tong ◽  
Xiang-Tian Kong ◽  
Yufeng Zhou ◽  
Fabiola Navarro-Pardo ◽  
Gurpreet Singh Selopal ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Quantum Dots ◽  
Near Infrared ◽  
Core Shell ◽  
Metal Free ◽  
Energy Mater

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>

Benzylamine-Free, Heavy-Metal-Free Synthesis of CL-20

2006 ◽  
Author(s):  
Robert D. Chapman ◽  
Richard A. Hollins ◽  
Thomas J. Groshens ◽  
David A. Nissan
Keyword(s):  
Heavy Metal ◽  
Metal Free

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.

Optical Temperature Sensing of Core-Shell Structured NaYF4:Yb3+, Er3+@NaYF4 Nanocrystals with Different Shell Thickness

2015 ◽  
Vol 738-739 ◽  
pp. 27-30
Author(s):  
Dong Dong Li ◽  
Qi Yue Shao ◽  
Yan Dong ◽  
Jian Qing Jiang
Keyword(s):  
Shell Thickness ◽  
Thermal Sensitivity ◽  
Upconversion Luminescence ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Sensing Properties ◽  
The Core ◽  
Β Phase ◽  
Biomedical Fields

Hexagonal (β)-phase NaYF4:Yb3+, Er3+ upconversion nanoparticles (UCNPs) with and without an inert (undoped NaYF4) shell have been successfully synthesized and the effects of shell thickness on the upconversion luminescence (UCL) and temperature sensing properties were systematically investigated. It was found that the NaYF4 shell and its thickness do not affect the RHS values and thermal sensitivity, but can obviously improve the UCL intensity of NaYF4:Yb3+, Er3+ UCNPs. It implies that the core-shell structured NaYF4:Yb3+, Er3+@NaYF4 UCNPs with excellent UCL properties have great potential to be used as temperature sensing probes in biomedical fields, without considering the influences of the shell thickness on their temperature sensing properties.

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