The optical limitation effect and features of luminescence kinetics in hybrid nanosystems with CdSe/ZnS quantum dots and organic agents

2013 ◽  
Vol 114 (6) ◽  
pp. 880-885 ◽  
Author(s):  
V. V. Danilov ◽  
A. S. Panfutova ◽  
G. M. Ermolaeva ◽  
A. I. Khrebtov ◽  
V. B. Shilov
Keyword(s):  
Quantum Dots ◽  
Luminescence Kinetics ◽  
Optical Limitation ◽  
Hybrid Nanosystems

scholarly journals Размерно-зависимые оптические свойства коллоидных квантовых точек CdS, пассивированных тиогликолевой кислотой

2018 ◽  
Vol 52 (9) ◽  
pp. 1015
Author(s):  
Т.С. Кондратенко ◽  
М.С. Смирнов ◽  
О.В. Овчинников ◽  
Е.В. Шабуня-Клячковская ◽  
А.С. Мацукович ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Cubic Crystal ◽  
Luminescence Kinetics ◽  
Donor Acceptor ◽  
Colloidal Cds

AbstractThe results of studies of the optical properties of ensembles of colloidal CdS quantum dots passivated by thioglycolic acid are reported. The average dimensions of the quantum dots lie in the range from 1.7 to 5.8 nm. By X-ray diffraction studies and Raman spectroscopy, it is established that quantum dots crystallize with the formation of a cubic crystal lattice. The systematic features of the quantum-confinement effect in the optical absorption and luminescence spectra, as well as in the luminescence excitation spectra, are established. The features manifest themselves as a blue shift of the corresponding bands with decreasing quantum-dot dimensions. From analysis of the nanosecond luminescence kinetics, it is concluded that experimentally observed radiative recombination proceeds by the donor–acceptor mechanism.

scholarly journals Luminescence kinetics of CdSe-based quantum dots in toluene

2018 ◽  
Vol 1068 ◽  
pp. 012013
Author(s):  
A G Shmelev ◽  
D K Zharkov ◽  
A V Leontyev ◽  
V G Nikiforov ◽  
V S Lobkov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Luminescence Kinetics ◽  
Kinetics Of

Effect of Cd0.5Zn0.5S shells on temperature-dependent luminescence kinetics of CdSe quantum dots

RSC Advances ◽  
2014 ◽  
Vol 4 (82) ◽  
pp. 43800-43805 ◽  
Author(s):  
Ping Yang ◽  
Hsueh-Shih Chen ◽  
Sha Zhang ◽  
Jie Zhao ◽  
Yingying Du ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
Temperature Dependent ◽  
Luminescence Kinetics ◽  
Kinetics Of

Highly Luminescent CdSe/ZnSe Core–Shell Quantum Dots of One-Pot Preparation in Octadecene

2008 ◽  
Vol 8 (3) ◽  
pp. 1346-1349 ◽  
Author(s):  
Qinghui Zeng ◽  
Xianggui Kong ◽  
Youlin Zhang ◽  
Hong Zhang
Keyword(s):  
Quantum Dots ◽  
Shell Thickness ◽  
Zinc Stearate ◽  
Core Shell ◽  
One Pot ◽  
New Approach ◽  
The Core ◽  
Luminescence Kinetics ◽  
Reagent Cost

CdSe/ZnSe core–shell quantum dots were synthesized using a new one-pot procedure where the core was prepared in octadecene. A ZnSe shell around a CdSe nanoparticle was formed by the reaction of selenium-richness on the surfaces of CdSe nanoparticles with Zn2+ from the injected zinc stearate precursor. The optical properties, luminescence kinetics, and the effect of shell thickness of as-prepared QDs were studied, which verifies the high quality of the resulting QDs. The new approach is effective not only for preparing core/shell QDs, but also for reducing the complexity of synthesis, toxicity, and reagent cost.

scholarly journals Нелинейно-оптические свойства квантовых точек CdS/ZnS в матрице из высокомолекулярного поливинилпирролидона

2018 ◽  
Vol 52 (8) ◽  
pp. 865
Author(s):  
А.С. Кулагина ◽  
С.К. Евстропьев ◽  
Н.Н. Розанов ◽  
В.В. Власов
Keyword(s):  
Quantum Dots ◽  
Nonlinear Optical ◽  
Quantum Confinement Effect ◽  
Nonlinear Refraction ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Nonlinear Properties ◽  
Two Photon ◽  
Optical Limitation

AbstractSols containing core/shell CdS/ZnS semiconductor quantum dots are synthesized and their nonlinear properties, which are interesting for a large variety of applications in nanophotonics, are studied. The quantum dots produced are smaller in dimensions than the exciton Bohr radius and, therefore, exhibit a well-pronounced quantum-confinement effect. The nonlinear optical properties of low-concentration sols are studied upon exposure to laser pulses with an emission wavelength of 532 nm and a duration of 5 ns by the z-scan technique. The dependences of nonlinear optical coefficients on the concentration of CdS/ZnS quantum dots are obtained. The intensity dependence of two-photon absorption coefficients is presented. The dependence determines the boundary of the influence of high-order nonlinearities on the nonlinear transmittance of the samples. The mechanisms of optical limitation exhibited by sols, specifically, two-photon absorption, nonlinear refraction, and nonlinear scattering are discussed.

scholarly journals Microwave-assisted one-pot synthesis of hybrid nanosystems based on CdS quantum dots functionalized with organic chromophores: effect of the chromophore nature on the nanosystem composition

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 2236-2241 ◽  
Author(s):  
Oleg V. Chashchikhin ◽  
Mikhail F. Budyka ◽  
Tatiana N. Gavrishova ◽  
Vitalii M. Li
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Organic Dye ◽  
Cds Quantum Dots ◽  
One Pot ◽  
Organic Chromophores ◽  
Microwave Assisted ◽  
One Pot Synthesis ◽  
Hybrid Nanosystems ◽  
Pot Technique

Quantum dot/organic dye nanosystems were synthesised via a one-pot technique. Different dependences of the nanosystem composition on the synthetic conditions for different dyes were observed.

Nanostructure of semiconductor quantum dots in a borosilicate glass matrix by complementary use of HREM and AEM

1990 ◽  
Vol 48 (4) ◽  
pp. 728-729
Author(s):  
M.J. Kim ◽  
L.C. Liu ◽  
S.H. Risbud ◽  
R.W. Carpenter
Keyword(s):  
Quantum Dots ◽  
Borosilicate Glass ◽  
Glass Matrix ◽  
Optical Switching ◽  
Response Times ◽  
Fast Response ◽  
Processing Technique ◽  
Internal Stresses ◽  
Electron Hole ◽  
Spatial Dimensions

When the size of a semiconductor is reduced by an appropriate materials processing technique to a dimension less than about twice the radius of an exciton in the bulk crystal, the band like structure of the semiconductor gives way to discrete molecular orbital electronic states. Clusters of semiconductors in a size regime lower than 2R {where R is the exciton Bohr radius; e.g. 3 nm for CdS and 7.3 nm for CdTe) are called Quantum Dots (QD) because they confine optically excited electron- hole pairs (excitons) in all three spatial dimensions. Structures based on QD are of great interest because of fast response times and non-linearity in optical switching applications.In this paper we report the first HREM analysis of the size and structure of CdTe and CdS QD formed by precipitation from a modified borosilicate glass matrix. The glass melts were quenched by pouring on brass plates, and then annealed to relieve internal stresses. QD precipitate particles were formed during subsequent "striking" heat treatments above the glass crystallization temperature, which was determined by differential thermal analysis.

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