Hole-filling of persistent spectral holes in the excitonic absorption band of CuBr quantum dots

1997 ◽  
Vol 70 (6) ◽  
pp. 680-682 ◽  
Author(s):  
J. Valenta ◽  
J. Moniatte ◽  
P. Gilliot ◽  
R. Levy ◽  
B. Hönerlage ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Absorption Band ◽  
Hole Filling ◽  
Excitonic Absorption ◽  
Excitonic Absorption Band

scholarly journals Temperature-induced shift of the exciton absorption band in InP/ZnS quantum dots

2017 ◽  
Vol 7 (2) ◽  
pp. 354 ◽  
Author(s):  
S. S. Savchenko ◽  
A. S. Vokhmintsev ◽  
I. A. Weinstein
Keyword(s):  
Quantum Dots ◽  
Absorption Band ◽  
Exciton Absorption ◽  
Exciton Absorption Band

scholarly journals CdSe/ZnS Quantum Dots As a Fluorescence Probes For Determination of Vitamin B1

2021 ◽  
Author(s):  
Reza Tirbandpaya ◽  
Abdolraouf Samadi-Maybodi
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Vitamin B1 ◽  
Fluorescence Probes ◽  
Fast Method ◽  
Excitonic Absorption ◽  
Wet Chemical ◽  
Excitonic Absorption Peak

Abstract This paper presents a new and fast method for determination of vitamin B1 (thiamine) using functionalized CdSe/ZnS quantum dots (QDs) as a sensor. In this study the core-shell CdSe/ZnS QDs with thioglycolic acid capping agents were synthesized by wet chemical method in aqueous solution. Electronic absorption was applied for size determination of the QDs, the average diameters of the synthesized quantum dots were calculated using wavelength of the first excitonic absorption peak. The methods of FESEM and FTIR were also used for characterization of the prepared samples. The results indicated that vitamin B1 could effectively quench the QDs emission and the fluorescence intensity decreased linearly with the concentration of vitamin B1 ranging from 10-7 to 10-4 molL−1 with limit of detection of 2×10-8 mol L−1. Determination of vitamin B1in pills from two pharmaceutical companies were used as real samples using this method .

scholarly journals Excitonic absorption in gate-controlled graphene quantum dots

2010 ◽  
Vol 82 (15) ◽  
Author(s):  
A. D. Güçlü ◽  
P. Potasz ◽  
P. Hawrylak
Keyword(s):  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Excitonic Absorption

scholarly journals Carbon quantum dots as a fluorophore for “inner filter effect” detection of metronidazole in pharmaceutical preparations

RSC Advances ◽  
2019 ◽  
Vol 9 (65) ◽  
pp. 38174-38182 ◽  
Author(s):  
Jianghong Tang ◽  
Yaheng Zhang ◽  
Yuhai Liu ◽  
Dan Liu ◽  
Hengfei Qin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Absorption Band ◽  
Hydrothermal Process ◽  
Pharmaceutical Preparations ◽  
Inner Filter Effect ◽  
Carbon Quantum Dots ◽  
Houttuynia Cordata ◽  
Filter Effect

CDs were prepared using Houttuynia cordata via hydrothermal process, the absorption band of MNZ can well overlap the excitation bands of CDs, a simple, rapid approach for detection of MNZ was established on the basis of IFE.

scholarly journals Broadband Terahertz Absorber Using Superimposed Graphene Quantum Dots

2021 ◽  
Author(s):  
Hadi Deljoo ◽  
Ali Rostami
Keyword(s):  
Quantum Dots ◽  
Absorption Band ◽  
Dielectric Material ◽  
Layer Structure ◽  
Graphene Quantum Dots ◽  
Middle Layer ◽  
Bottom Layer ◽  
Broadband Absorption ◽  
Terahertz Absorber ◽  
Simulation Results

Abstract In this study, we propose and investigate numerically a broadband THz metamaterial-based absorber, which is composed of superimposed Graphene Quantum Dots. Based on this idea, a new way to engineering the absorption band is introduced. We will show that using the proposed idea, it is possible to design a THz absorber with a given bandwidth. To show the capability of the idea, we consider a three-layer structure, and the top layer is superimposed graphene disks. The middle layer is a lossless dielectric thin layer and eventually gold is placed in the bottom layer. Simulation results reveal a broadband absorption in the range of (5.86THz to 7.57THz), (5.89THz to 7.56THz), and (5.89THz to 7.58THz) while absorption values respectively are above 89%, 88.49%, and 88.32%. The dielectric material is Si3N4 in the proposed structure. Also, the broadband absorption range is 7.47THz to 9.87THz with an absorption value above 80% while the dielectric material is SiO2.

scholarly journals Influence of Size and Shape Anisotropy on Optical Properties of CdSe Quantum Dots

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1589 ◽  
Author(s):  
Sung Hun Kim ◽  
Minh Tan Man ◽  
Joong Wook Lee ◽  
Kyoung-Duck Park ◽  
Hong Seok Lee
Keyword(s):  
Quantum Dots ◽  
Shape Anisotropy ◽  
Phosphine Ligands ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Estimation Errors ◽  
Excitonic Absorption ◽  
Quantum Size ◽  
Diffraction Patterns ◽  
Xrd Patterns

We used low-temperature reactions to synthesize different-sized CdSe quantum dots (QDs) capped with fatty-acid and phosphine ligands. From the correlation of high-resolution transmission electron microscopy and X-ray diffraction (XRD) analyses of the synthesized QDs, we observed size-dependent shape anisotropy. In addition, the recorded XRD patterns revealed mixed crystal facets with zinc blende and wurtzite structures in small-sized QDs. Furthermore, from differential absorption (DA) spectra, we extracted the electronic transition energies for different-sized QDs, which were found to be similar to the calculated values of the quantum size levels associated with band mixing of CdSe QDs with a moderate bandgap. We found that the excitonic absorption peaks are increasingly “hidden” with decreasing QD size because of the crystal structure and crystalline quality. The results show good agreement with the obtained diffraction patterns and the estimation errors obtained from the DA spectra.

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