Temperature-dependent recombination dynamics and electroluminescence characteristics of colloidal CdSe/ZnS core/shell quantum dots

2021 ◽  
Vol 119 (7) ◽  
pp. 073303
Author(s):  
Jialin Wu ◽  
Lixiang Chen ◽  
Yongshuang Zhao ◽  
Zuhong Xiong ◽  
Wenyu Ji ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Core Shell ◽  
Temperature Dependent ◽  
Recombination Dynamics

Photoluminescence Properties of Core/Shell CdSe/ZnS Quantum Dots Encapsulated with Transparent layers for Third Generation Photovoltaics

2011 ◽  
Vol 1322 ◽  
Author(s):  
Bahareh Sadeghimakki ◽  
Navid Mohammad Sadeghi Jahed ◽  
Siva Sivoththaman
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Synthesis Method ◽  
Core Shell ◽  
Temperature Dependent ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Intense Luminescence ◽  
Excitonic Emission ◽  
Third Generation Photovoltaics

ABSTRACTIn this work hydrophobicaly ligated cadmium selenide/zinc sulfide CdSe/ZnS quantum dots (QDs) were incorporated in transparent matrices by formation of CdSe/ZnS/SiO2 core/shell/shell structure using microemolsion synthesis method. The optical properties of the QDs encapsulated with a chemically grown oxide layers were studied. Intense luminescence properties of the QD/silica nanoparticles (NPs) were observed using steady state photoluminescence (PL) measurements. Confocal microscopy demonstrates fluorescence of the single core/shell/shell nanoparticles. The obtained results along with the Secondary Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images provide information on the geometry of the QDs. The excitonic emission of nanoparticles was also mapped using a liquid nitrogen cryostat the 77K - 300K range. The temperature dependent PL spectra of the film demonstrate the temperature-dependent band gap shrinkage of the QDs. PL lifetime measurements were performed on the ensemble of NPs. Experimental data was fitted to the numerical model with lifetime constants in nanoseconds range. We demonstrate that the main nonradiative processes that limit the quantum yield (QY) of the QDs at room temperature are the carrier trapping at the interface of QD/silica and the exciton-phonon coupling. These studies give us insight to exploit the QD layers for photon down shifting and multiple exciton generation for application in photovoltaics.

scholarly journals Temperature-Dependent Recombination Processes in Small-Sized PbSe/PbS Core/Shell Colloidal Quantum Dots

2014 ◽  
Vol 20 (2) ◽  
Author(s):  
Diana YANOVER ◽  
Anna RUBIN-BRUSILOVSKI ◽  
Richard ČAPEK ◽  
Aldona SASHCHIUK ◽  
Efrat LIFSHITZ
Keyword(s):  
Quantum Dots ◽  
Colloidal Quantum Dots ◽  
Core Shell ◽  
Temperature Dependent ◽  
Recombination Processes

Temperature-dependent resonance energy transfer from CdSe–ZnS core–shell quantum dots to monolayer MoS2

Nano Research ◽  
2016 ◽  
Vol 9 (9) ◽  
pp. 2623-2631 ◽  
Author(s):  
Juan Li ◽  
Weina Zhang ◽  
Yao Zhang ◽  
Hongxiang Lei ◽  
Baojun Li
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Core Shell ◽  
Monolayer Mos2 ◽  
Temperature Dependent

Shell-dependent blinking behavior and fluorescence dynamics of single ZnSe/CdS core/shell quantum dots

Nanoscale ◽  
2018 ◽  
Vol 10 (39) ◽  
pp. 18696-18705 ◽  
Author(s):  
Xing Guo ◽  
Yanmin Kuang ◽  
Sheng Wang ◽  
Zhaohan Li ◽  
Huaibin Shen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Shell Thickness ◽  
Core Shell ◽  
Cds Quantum Dots ◽  
Emission Properties ◽  
Exciton Recombination ◽  
Recombination Dynamics

Shell thickness regulates the exciton recombination dynamics, blinking behaviors and emission properties of ZnSe/CdS quantum dots.

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
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