Photoinduced photoluminescence intensity enhancement in poly(p-phenylene vinylene) films

2002 ◽  
Vol 81 (5) ◽  
pp. 942-944 ◽  
Author(s):  
Y. Galvão Gobato ◽  
A. Marletta ◽  
R. M. Faria ◽  
F. E. G. Guimarães ◽  
J. M. de Souza ◽  
...  
Keyword(s):  
Phenylene Vinylene ◽  
Photoluminescence Intensity ◽  
Intensity Enhancement

Photoinduced Enhancement of Photoluminescence Intensity in PPV Films

2001 ◽  
Vol 665 ◽  
Author(s):  
Yara Galvão Gobato ◽  
Alexandre Marletta ◽  
Jucimar M. Souza ◽  
Ernesto Pereira ◽  
Roberto M. Faria ◽  
...  
Keyword(s):  
Laser Power ◽  
Blue Shift ◽  
Sample Thickness ◽  
Phenylene Vinylene ◽  
Photoluminescence Intensity ◽  
Carbonyl Groups ◽  
Conjugation Length ◽  
Ion Laser ◽  
Pl Intensity ◽  
Effective Conjugation Length

ABSTRACTPoly(p-phenylene vinylene) (PPV) films are usually photodegraded in air. We report on the enhancement of photoluminescence (PL) intensity of PPV films induced by Ar ion laser in the presence of air. The PL spectra were measured as function of laser power, time exposure and sample thickness. The initial PL intensity increases up to 300% without significant changes in peak positions by optimizing such parameters. This effect is accompanied by a blue-shift in the absorption spectrum resulting in shortened effective conjugation length and by a formation of defects such as carbonyl groups. Mechanisms for the observed photoluminescence intensity enhancements are suggested.

scholarly journals Effect of uniform magnetic field on laser-produced Cu plasma and the deposited particles on the target surface

2017 ◽  
Vol 35 (2) ◽  
pp. 352-361 ◽  
Author(s):  
K.S. Singh ◽  
A. Khare ◽  
A.K. Sharma
Keyword(s):  
Magnetic Field ◽  
Target Surface ◽  
Peripheral Region ◽  
Impact Excitation ◽  
Rate Coefficients ◽  
Electron Impact Excitation ◽  
Photoluminescence Intensity ◽  
Excitation Rate ◽  
Intensity Enhancement ◽  
The Difference

AbstractLaser-produced copper plasma in the presence of variable transverse external magnetic field in air is investigated using optical emission spectroscopy. As the magnetic field increases from 0 to 0.5 T, the intensity of Cu I lines initially increases and then decreases slightly at a 0.5 T. The maximum intensity enhancement of all five Cu I lines occurs at a magnetic field of 0.3 T. The increase in intensity is attributed to an increase in the electron impact excitation of Cu. With increase in magnetic field, the electron density and temperature were found to increase due to increase in the confinement of plasma. The difference in intensity enhancement factor is due to the difference in excitation rate coefficients. The surface morphology of irradiated copper target is also analyzed at 0.3 T magnetic field at which the density is maximum and reveals the formation of Cu/Cu2O/CuO nanoparticles (NPs). More NPs are formed at the peripheral region than at the central region of the ablated crater and is due to the oxidation of Cu atom in the plasma–ambient interface. The larger grain size of nanostructures in the presence of magnetic field is due to an increase in the inverse pulsed laser deposition. The intensity of Raman peak of Cu2O decreases in the presence of magnetic field and that of CuO increases which is more likely due to conversion of Cu2O to CuO. The photoluminescence intensity of CuO increases in the presence of magnetic field due to the phase transformation of Cu2O to CuO in agreement with the result of Raman spectroscopy.

Room temperature photoluminescence intensity enhancement in GaAs1-xBix alloys

2011 ◽  
Vol 9 (2) ◽  
pp. 259-261 ◽  
Author(s):  
A. R. Mohmad ◽  
F. Bastiman ◽  
J. S. Ng ◽  
S. J. Sweeney ◽  
J. P. R. David
Keyword(s):  
Room Temperature ◽  
Photoluminescence Intensity ◽  
Room Temperature Photoluminescence ◽  
Intensity Enhancement

Photoluminescence intensity enhancement by electron beam irradiation into GaAs quantum wells

1999 ◽  
Vol 43 (1) ◽  
pp. 147-152 ◽  
Author(s):  
Tomohiro Murata ◽  
Yutaka Ohno ◽  
Shigeru Kishimoto ◽  
Takashi Mizutani
Keyword(s):  
Electron Beam ◽  
Quantum Wells ◽  
Electron Beam Irradiation ◽  
Photoluminescence Intensity ◽  
Beam Irradiation ◽  
Intensity Enhancement

Photoluminescence intensity enhancement in SWNT aqueous suspensions due to reducing agent doping: Influence of adsorbed biopolymer

2014 ◽  
Vol 438 ◽  
pp. 23-30 ◽  
Author(s):  
N.V. Kurnosov ◽  
V.S. Leontiev ◽  
A.S. Linnik ◽  
O.S. Lytvyn ◽  
V.A. Karachevtsev
Keyword(s):  
Reducing Agent ◽  
Photoluminescence Intensity ◽  
Intensity Enhancement ◽  
Aqueous Suspensions

Photoluminescence Intensity Enhancement of Single Silicon Quantum Dots on a Metal Membrane with a Spacer

2019 ◽  
Vol 217 (4) ◽  
pp. 1900575
Author(s):  
Jingjian Zhou ◽  
Federico Pevere ◽  
Hithesh K. Gatty ◽  
Jan Linnros ◽  
Ilya Sychugov
Keyword(s):  
Quantum Dots ◽  
Photoluminescence Intensity ◽  
Silicon Quantum Dots ◽  
Metal Membrane ◽  
Intensity Enhancement
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