Probing the Structure of Colloidal Core/Shell Quantum Dots Formed by Cation Exchange

2012 ◽  
Vol 116 (6) ◽  
pp. 3968-3978 ◽  
Author(s):  
Keith A. Abel ◽  
Paul A. FitzGerald ◽  
Ting-Yu Wang ◽  
Tom Z. Regier ◽  
Mati Raudsepp ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cation Exchange ◽  
Core Shell

scholarly journals Utilizing Cation Exchange Method to Produce Core/Shell PbS/CdS Quantum Dots with Stable Infrared Emission

2013 ◽  
Vol 71 (06) ◽  
pp. 929
Author(s):  
Qian Li ◽  
Teng Zhang ◽  
Hongwei Gu ◽  
Fazhu Ding ◽  
Fei Qu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cation Exchange ◽  
Infrared Emission ◽  
Core Shell ◽  
Cds Quantum Dots ◽  
Exchange Method

Colloidal Synthesis of Giant Shell PbSe-Based Core/Shell Quantum Dots in Polar Solvent: Cation Exchange versus Epitaxial Growth

2020 ◽  
Vol 32 (15) ◽  
pp. 6650-6656
Author(s):  
Dong Li ◽  
Xiaoli Zhang ◽  
Muhammad Ramzan ◽  
Kai Gu ◽  
Yu Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cation Exchange ◽  
Epitaxial Growth ◽  
Polar Solvent ◽  
Colloidal Synthesis ◽  
Core Shell

Tailoring ZnSe–CdSe Colloidal Quantum Dots via Cation Exchange: From Core/Shell to Alloy Nanocrystals

ACS Nano ◽  
2013 ◽  
Vol 7 (9) ◽  
pp. 7913-7930 ◽  
Author(s):  
Esther Groeneveld ◽  
Leon Witteman ◽  
Merel Lefferts ◽  
Xiaoxing Ke ◽  
Sara Bals ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cation Exchange ◽  
Colloidal Quantum Dots ◽  
Core Shell ◽  
Alloy Nanocrystals

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>

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