Solvent-enhanced Dye Diffusion in Polymer This-Films for OLED Application

2001 ◽  
Vol 665 ◽  
Author(s):  
F. Pschenitzka ◽  
K. Long ◽  
J. C. Sturm
Keyword(s):  
Polymer Film ◽  
Light Emitting Diode ◽  
Nile Red ◽  
Dye Transfer ◽  
Solvent Vapor ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Solvent Absorption ◽  
Dye Diffusion ◽  
Materials Used

ABSTRACTA method of solvent-enhanced dye diffusion in polymer films for organic light-emitting diode (OLED) application is introduced. After an initial dye transfer from a dye source substrate into the top of the electractive polymer film, the device substrate is then exposed to solvent vapor. Due to solvent absorption by the polymer film, the glass transition temperature of the polymer is significantly decreased, which leads to greatly enhanced diffusion of the dye in the polymer film. Secondary ion mass spectroscopy shows that the temperature for dye diffusion can be decreased by 150 °C. OLEDs with 0.4% external quantum efficiency were demonstrated. The materials used are the polymer poly(9-vinylcarbazole) (PVK) combined with electron transport molecules (PBD), and the dyes coumarin 47, coumarin 6 and Nile red.

Anomalous Temperature Dependence of Solvent-Enhanced Dye Diffusion In Polymer Films

2002 ◽  
Vol 725 ◽  
Author(s):  
T. Graves-Abe ◽  
F. Pschenitzka ◽  
J.C. Sturm
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Temperature Dependence ◽  
Polymer Film ◽  
Light Emitting Diode ◽  
Solvent Vapor ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Driven

AbstractOne promising method to pattern full color polymer Organic Light-Emitting Diode (OLED) displays is to print dye from a pre-patterned organic film onto a spin-cast polymer and then diffuse the dye into the film at room temperature in a solvent vapor environment. This method utilizes the well-known tendency for a polymer film to absorb solvent vapor, which depresses the glass transition temperature of the polymer and dramatically increases diffusion the dye. In this work, we have studied the temperature dependence of this process. The dye coumarin 6 (C6) was transferred onto films consisting of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)- 1,3,4-oxadiazole (PBD) mixed with the polymer poly(9-vinylcarbazole) (PVK). Samples were then placed on a heated stage in a chamber and exposed to acetone vapor to diffuse the C6 into the polymer film. The profile of the diffused dye was determined by depthdependent photoluminescence measurements and Secondary Ion Mass Spectroscopy. We observed that the amount of diffused dye decreased at higher temperatures, in contrast to conventional thermally-driven diffusion. The results are understood by noting that the decrease in the polymer glass-transition temperature and the corresponding rapid increase in dye diffusivity depend on the quantity of solvent absorbed by the polymer, which decreases as the temperature of the polymer is raised.

Three-Color Doping of Polymer Oleds by Masked Dye Diffusion

1999 ◽  
Vol 558 ◽  
Author(s):  
F. Pschenitzka ◽  
J. C. Sturm
Keyword(s):  
Polymer Film ◽  
Nile Red ◽  
Organic Light Emitting Diodes ◽  
Large Area ◽  
Light Emitting ◽  
Dye Diffusion ◽  
Materials Used ◽  
Integrated Device ◽  
Coumarin 6 ◽  
Transport Molecules

ABSTRACTA method to locally pattern the distribution of dye by diffusion into the polymer film of organic light-emitting diodes is introduced. Using a large-area diffusion source, the diffusion of dye into the polymer film can be controlled with a shadow mask. The materials used are the polymer poly(9-vinylcarbazole) (PVK) combined with electron transport molecules (PBD), and the dyes bimane, coumarin 6 and Nile red. The temperature dependence of the diffusion is investigated along with the effect of annealing of the polymer film. A model of the dye distribution is introduced and estimations of the dye profile based on this model and PL measurement are discussed. A 3-color integrated device was demonstrated.

scholarly journals Unravelling the electron injection/transport mechanism in organic light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tsubasa Sasaki ◽  
Munehiro Hasegawa ◽  
Kaito Inagaki ◽  
Hirokazu Ito ◽  
Kazuma Suzuki ◽  
...  
Keyword(s):  
Work Function ◽  
Transport Mechanism ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Materials Used

AbstractAlthough significant progress has been made in the development of light-emitting materials for organic light-emitting diodes along with the elucidation of emission mechanisms, the electron injection/transport mechanism remains unclear, and the materials used for electron injection/transport have been basically unchanged for more than 20 years. Here, we unravelled the electron injection/transport mechanism by tuning the work function near the cathode to about 2.0 eV using a superbase. This extremely low-work function cathode allows direct electron injection into various materials, and it was found that organic materials can transport electrons independently of their molecular structure. On the basis of these findings, we have realised a simply structured blue organic light-emitting diode with an operational lifetime of more than 1,000,000 hours. Unravelling the electron injection/transport mechanism, as reported in this paper, not only greatly increases the choice of materials to be used for devices, but also allows simple device structures.

Design, Synthesis and Properties of Asymmetric Substituted Coronene Derivative as Discotic Liquid Crystal

2010 ◽  
Vol 428-429 ◽  
pp. 75-78
Author(s):  
Wen Guang Wang ◽  
Xu Ying Liu ◽  
Ling Liu ◽  
Jia Ling Pu
Keyword(s):  
Liquid Crystal ◽  
Light Emitting Diode ◽  
Building Blocks ◽  
Design Synthesis ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Discotic Liquid Crystal ◽  
Organic Light ◽  
Effect Transistor ◽  
Materials Used

Asymmetric substituted coronenes as building blocks for preparation of materials used as functional molecular devices in the fields of self-organization, organic light-emitting diode, photovoltaic solar cell and field effect transistor are easily converted to potential interesting coronene’s derivatives. A novel kind of derivative of dibenzocoronene with perylene tetracarboxdiimide as discotic liquid crystal with two kinds of soft and long chains was designed and synthesized. Its structure was confirmed by 1HNMR and IR. Its UV-vis was measured. Its properties as discotic liquid crystal are investigated in progress.

Flexible Organic Light Emitting Diode (OLED) Display

2012 ◽  
Vol 132 (2) ◽  
pp. 77-80
Author(s):  
Hajime YAMAGUCHI ◽  
Kentaro MIURA ◽  
Tomomasa UEDA
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Oled Display

Effects of Nitridation Time on Top-emission Inverted Organic Light Emitting Diode

PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 821-824 ◽  
Author(s):  
Chien-Chang Tseng ◽  
Liang-Wen Ji ◽  
Yu Sheng Tsai ◽  
Fuh-Shyang Juang
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Nitridation Time ◽  
Organic Light
Sign in / Sign up

Export Citation Format

Share Document