Photoluminescence intensity and multiple phonon Raman scattering in quantum dots: evidence of the bottleneck effect

1994 ◽  
Vol 305 (1-3) ◽  
pp. 585-590 ◽  
Author(s):  
P.D. Wang ◽  
C.M.Sotomayor Torres ◽  
H. McLelland ◽  
S. Thoms ◽  
M. Holland ◽  
...  
2015 ◽  
Vol 60 (12) ◽  
pp. 1224-1233
Author(s):  
Yu.A. Romanyuk ◽  
◽  
A.M. Yaremko ◽  
V.M. Dzhagan ◽  
V.O. Yukhymchuk ◽  
...  

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1274
Author(s):  
Grigor A. Mantashian ◽  
Paytsar A. Mantashyan ◽  
Hayk A. Sarkisyan ◽  
Eduard M. Kazaryan ◽  
Gabriel Bester ◽  
...  

By using the numerical discretization method within the effective-mass approximation, we have theoretically investigated the exciton-related Raman scattering, interband absorption and photoluminescence in colloidal CdSe/CdS core/shell quantum dots ensemble. The interband optical absorption and photoluminescence spectra have been revealed for CdSe/CdS quantum dots, taking into account the size dispersion of the ensemble. Numerical calculation of the differential cross section has been presented for the exciton-related Stokes–Raman scattering in CdSe/CdS quantum dots ensemble with different mean sizes.


2016 ◽  
Vol 16 (4) ◽  
pp. 3457-3467 ◽  
Author(s):  
Jigang Wang ◽  
Ji Zhou ◽  
Wenhua Zhou ◽  
Jilong Shi ◽  
Lun Ma ◽  
...  

Chemical derived graphene oxide, an atomically thin sheet of graphite with two-dimensional construction, offers interesting physical, electronic, thermal, chemical, and mechanical properties that are currently being explored for advanced physics electronics, membranes, and composites. Herein, we study graphene quantum dots (GQD) with the blue photoluminescence under various parameters. The GQD samples were prepared at different temperatures, and the blue photoluminescence intensity of the solution improved radically as the heating temperatures increased. Concerning PL peak and intensity of the quantum dots, the results demonstrated dependence on time under heating, temperature of heating, and pH adjusted by the addition of sodium hydroxide. After hydrothermal synthesis routes, the functional groups of graphene oxide were altered the morphology showed the stacking configuration, and self-assembled structure of the graphene sheets with obvious wrinkles appeared at the edge structures. In addition, absorption, PL, and PLE spectra of the graphene quantum dots increase with different quantities of sodium hydroxide added. Finally, using GQD to target PNTIA cells was carried out successfully. High uptake efficiency and no cytotoxic effects indicate graphene quantum dots can be suitable for bio-targeting.


JETP Letters ◽  
2003 ◽  
Vol 77 (3) ◽  
pp. 143-145 ◽  
Author(s):  
L. K. Vodop’yanov ◽  
V. S. Vinogradov ◽  
N. N. Mel’nik ◽  
G. Karczewski

2018 ◽  
Vol 50 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Fabing Li ◽  
Ying Wang ◽  
Zhanlong Li ◽  
Wenhui Fang ◽  
Yeqiu Li ◽  
...  

2011 ◽  
Vol 25 (32) ◽  
pp. 4387-4393 ◽  
Author(s):  
HAI-CHAO SUN ◽  
CUI-HONG LIU

The differential cross section (DCS) for exciton-mediated Raman scattering (EMRS) in one-dimensional semiconductor quantum dots is presented. The exciton states are considered as intermediate states in the Raman scattering process. The selection rules for the EMRS process are studied. The numerical results show that the contribution to DCS indicated by exciton is larger than that by electron. DCS of EMRS is larger when there is a bigger confinement potential frequency.


2007 ◽  
Vol 76 (15) ◽  
Author(s):  
P. D. Lacharmoise ◽  
A. Bernardi ◽  
A. R. Goñi ◽  
M. I. Alonso ◽  
M. Garriga ◽  
...  

2017 ◽  
Vol 17 (2) ◽  
pp. 1140-1148
Author(s):  
K Monsalve-Calderón ◽  
A Gil-Corrales ◽  
A.L Morales ◽  
R.L Restrepo ◽  
M. E Mora-Ramos ◽  
...  

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