Light Emitting thin Film Devices Based on Self-assembled Multilayer Heterostructures of PPV

1995 ◽  
Vol 413 ◽  
Author(s):  
M. Ferreira ◽  
O. Onitsuka ◽  
A. C. Fou ◽  
B. Hsieh ◽  
M. F. Rubner
Keyword(s):  
Thin Film ◽  
Carrier Transport ◽  
Thermal Conversion ◽  
Layer By Layer ◽  
Light Emitting ◽  
Hole Transporting ◽  
Improved Performance ◽  
And Performance ◽  
P Type ◽  
Thin Film Devices

ABSTRACTPPV based light emitting thin film devices were fabricated using a layer-by-layer deposition technique involving the alternate spontaneous adsorption of a PPV precursor polymer and either poly(styrene-4-sulfonate) (SPS) or poly(methacrylic acid) (PMA). It was demonstrated that the polyanion used to self-assemble the PPV precursor strongly influences the characteristics and performance of the resulting LEDs. Devices fabricated with PPV created in the presence of SPS exhibited symmetric I–V curves, low luminance levels and very high current densities while PPV/PMA devices exhibited luminance levels in the range of 10–60 cd/m2 and classical rectifying behavior. These dramatic differences are primarily due to a low level of p-type doping activated during the thermal conversion of PPV and/or during device operation that confers excellent hole carrier transport capabilities to the PPV/SPS combination. Fabrication of a multi-slab type heterostructure device comprised of a PPV/SPS block (hole transporting block) and a PPV/PMA block (emitting block) resulted in improved performance with luminance levels significantly higher than previously obtained for a single slab PPV/PMA device (typically > 100 cd/m2). It was also demonstrated that the presence of very thin (about 20–30 Å thick) insulating layers at the Al/polymer interface improves device efficiency by a factor of 2–4.

Investigations of New Self-Assembled Multilayer Thin Films Based on Alternately Adsorbed Layers of Polyelectrolytes and Functional Dye Molecules

1995 ◽  
Vol 413 ◽  
Author(s):  
Dongsik Yoo ◽  
Jin-kyu Lee ◽  
M. F. Rubner
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Assembly ◽  
Fluorescent Dyes ◽  
Multilayer Thin Films ◽  
Layer By Layer ◽  
Dye Molecules ◽  
Ph Indicator ◽  
Light Emitting ◽  
Thin Film Devices

ABSTRACTThe layer-by-layer self-assembly of a number of different functional dye molecules has been accomplished via the alternate spontaneous adsorption of polyelectrolytes and ionic dyes from dilute solutions. Multilayer thin films containing such functional dyes as pH indicator dyes, infrared absorbing dyes, porphyrin dyes and various fluorescent dyes have been successfully fabricated and their electrical and opt, 2al properties examined. Multilayers containing a newly synthesized ionic ruthenium based polypryidyl dye have been utilized to fabricate light emitting thin film devices with high brightness (ca. 100 cd/m2) at voltages in the range of 5–10 volts. These new light emitting thin film devices exhibit excellent stability when compared to devices based on conjugated polymers such PPV. The fabrication and device evaluation of new heterostructure thin films based on this new light emitting dye as well as the properties of other multilayer thin films containing dye molecules are presented.

Synthesis and Electrical Characterization of Multilayer Thin Films Designed by Layer-by-Layer Self Assembly of Nanoparticles

2010 ◽  
Vol 11 ◽  
pp. 1-6 ◽  
Author(s):  
Sujira Promnimit ◽  
Joydeep Dutta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Organization ◽  
Colloidal Nanoparticles ◽  
Multilayer Thin Films ◽  
Layer By Layer ◽  
Multilayer Thin Film ◽  
Research Attention ◽  
Onset Voltage ◽  
Thin Film Devices

In this work, we report the directed self organization of multilayer thin film devices with colloidal nanoparticles through Layer-by-Layer (LbL) technique [1]. Self-organization of nanoparticles into assemblies to create novel nanostructures is getting increasing research attention in microelectronics, medical, energy and environmental applications. Directed self-organization of nanoparticles [2] into multilayer thin films were achieved by LbL growth through the interaction of oppositely charged of colloidal nanoparticles on substrates of any kind and shapes. Multilayer thin film devices were fabricated using multilayers of gold (conducting) nanoparticles separated by a dielectric nanoparticulate layer of zinc sulphide. The thin films obtained have been studied extensively and the changes in surface morphology, the optical absorption characteristics, thickness, uniformity, adhesion, and conduction behavior are reported. Current voltage (I-V) characteristics of multilayer devices with an increasing number of deposition cycles show an initial current blockade until an onset voltage value, which increases linearly upon the additional layers stacked in devices [3]. A conductive behavior of the device was observed upon exceeding the onset voltage. Moreover, I-V behavior showed that the conduction onset voltage increases linearly depending on the numbers of layers in the final device controlled by the deposition cycles. Systematic I-V characteristics in the forward and reverse biased conditions demonstrated rectifying behaviors in the onset of conduction voltage which makes these films attractive for future electronic device applications.

P-type indium oxide thin film for the hole-transporting layer of organic solar cells

2012 ◽  
Vol 520 (7) ◽  
pp. 3118-3124 ◽  
Author(s):  
Pingli Qin ◽  
Guojia Fang ◽  
Nanhai Sun ◽  
Xi Fan ◽  
Qiao Zheng ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Indium Oxide ◽  
Organic Solar Cells ◽  
Oxide Thin Film ◽  
Hole Transporting ◽  
P Type ◽  
Indium Oxide Thin Film

Improved performance of organic light emitting diodes by pentacene as hole transporting layer

2008 ◽  
Vol 255 (5) ◽  
pp. 1942-1945 ◽  
Author(s):  
Fujun Zhang ◽  
Zheng Xu ◽  
Suling Zhao ◽  
Dewei Zhao ◽  
Guangcai Yuan ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Hole Transporting ◽  
Improved Performance

Fluorescence Quenching Based Thin Film Sensors Employing Electrostatic Layer-by-Layer Self-Assembly

2000 ◽  
Vol 660 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
J. Kumar ◽  
S. K. Tripathy
Keyword(s):  
Thin Film ◽  
Fluorescence Quenching ◽  
Chemical Sensors ◽  
Self Assembly ◽  
Linear Increase ◽  
Layer By Layer ◽  
Thin Film Sensors ◽  
Optical Chemical Sensors ◽  
And Performance ◽  
Bimolecular Quenching

ABSTRACTIn this work, the fabrication and performance of thin film optical chemical sensors based on the fluorescence quenching of indicator molecules by several analytes such as organic nitro compounds or metal ions are described. To fabricate the sensors, a fluorescent molecule, 1- hydroxypyrene-3,6,8-trisulfonate or pyrene methanol, was covalently incorporated into poly(acrylic acid) (PAA) and subsequently the polymers were assembled with a polycation employing electrostatic layer-by-layer self-assembly into thin film structures. Fluorescence intensities decreased with increasing concentration of analytes. Quenching behavior follows Stern-Volmer bimolecular quenching kinetics. Linear increase in absorbance, film thickness and emission intensity was observed with increase in number of bilayers deposited in all multilayer films.

Improved performance of organic light-emitting diodes using advanced hole-transporting materials

2009 ◽  
Vol 159 (23-24) ◽  
pp. 2578-2583 ◽  
Author(s):  
Seok-Hwan Hwang ◽  
Young Kook Kim ◽  
Yoonhyun Kwak ◽  
Chang-Ho Lee ◽  
Jonghyuk Lee ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Hole Transporting ◽  
Improved Performance ◽  
Hole Transporting Materials
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