scholarly journals Survey on Organic Light Emitting Diode

2020 ◽  
Vol 5 (6) ◽  
pp. 630-636
Author(s):  
Savithri Hande ◽  
Prajna K B
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
National Laboratory ◽  
Pacific Northwest National Laboratory ◽  
American Chemical Society ◽  
Department Of Energy ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Advantages And Disadvantages ◽  
Organic Light

Organic light emitting diodes is a new display technology, which uses organic thin materials that are placed between conductors. When an electric current is applied, a bright light is emitted. OLEDs are thin, transparent, flexible, foldable displays. In 1987 researchers of Eastman Kodak company invented OLED diode technology. The principal inventors were Chemists Ching W. Tang and Steven Van Slyke. In 2001 they received an Industrial Innovation Award from the American Chemical Society for their contribution in organic light emitting diodes. In 2003, Kodak realised its first OLED display had 512 by 218 pixels, 2.2 inch. Two technologies necessary to make flexible OLEDs were invented by Researchers at Pacific Northwest National Laboratory and the Department of Energy. Many researchers are contributing to improve the OLED technology. In this paper we give a brief of what is OLED, types of OLED, different fabrication methods of OLED, advantages and disadvantages of OLED.

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.

High efficiency above 20% in polymeric thermally activated delayed fluorescent organic light-emitting diodes by a host embedded backbone structure

2019 ◽  
Vol 10 (35) ◽  
pp. 4872-4878 ◽  
Author(s):  
Yun Hwan Park ◽  
Ho Jin Jang ◽  
Jun Yeob Lee
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Organic Light ◽  
Backbone Structure

A highly efficient polymeric thermally activated delayed fluorescent (TADF) organic light-emitting diode was developed by synthesizing a copolymer with 9-vinylcarbazole (VCz) and TADF repeating units.

A life estimation model applied to organic light-emitting diodes

2018 ◽  
Vol 51 (5) ◽  
pp. 764-773
Author(s):  
JP Zhang ◽  
Y Zong ◽  
Y Meng ◽  
WG Pan ◽  
JS Tang
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Decay Data ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Extrapolation Model ◽  
Accelerated Life

For predicting life for light-emitting devices quickly and accurately, a novel life prediction model, namely an extrapolation model of accelerated life and stress, has been proposed. In this model, a Weibull function is employed to fit luminance decay data under multiple groups of accelerated stresses, and the corresponding accelerated life is obtained. By determination coefficients and root mean square errors, a power function is determined as an extrapolated function to describe the relationship between accelerated life and stress and the life of the light-emitting devices. For organic light-emitting diodes, three groups of constant-stress accelerated degradation tests were conducted by increasing current stress. An extrapolation model of accelerated life and stress was applied to process the collected luminance decay data and was evaluated by a careful comparison with organic light-emitting diode life. The results indicate that the self-designed experimental scheme for organic light-emitting diode is feasible and versatile; the predicted life is 17,113 hours, which is close to the service life derived from user feedback, and the relative error is only 2.2%. This shows that the extrapolation model of accelerated life and stress has high precision; the model reveals the expected law of luminance changing with time and intuitively depicts the life characteristics under accelerated stresses without conventional life tests. This will pave the way for a new method to predict and evaluate the life of modern light-emitting devices.

High-resolution electrohydrodynamic jet printing of small-molecule organic light-emitting diodes

Nanoscale ◽  
2015 ◽  
Vol 7 (32) ◽  
pp. 13410-13415 ◽  
Author(s):  
Kukjoo Kim ◽  
Gyeomuk Kim ◽  
Bo Ram Lee ◽  
Sangyoon Ji ◽  
So-Yun Kim ◽  
...  
Keyword(s):  
High Resolution ◽  
Small Molecule ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Electrohydrodynamic Jet Printing ◽  
Jet Printing

An electrohydrodynamic jet (e-jet) printed high-resolution (pixel width of 5 μm) small-molecule organic light-emitting diode (OLED) is demonstrated.

Advantages and disadvantages of vacuum-deposited and spin-coated amorphous organic semiconductor films for organic light-emitting diodes

2015 ◽  
Vol 3 (42) ◽  
pp. 11178-11191 ◽  
Author(s):  
Maki Shibata ◽  
Yoshiya Sakai ◽  
Daisuke Yokoyama
Keyword(s):  
Organic Semiconductor ◽  
Molecular Orientation ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Transition Temperatures ◽  
Semiconductor Films ◽  
Light Emitting ◽  
Advantages And Disadvantages ◽  
Organic Light

Film densities, transition temperatures, and degrees of horizontal molecular orientation of vacuum-deposited and spin-coated amorphous organic semiconductor films used for OLEDs are systematically and quantitatively compared, and their general differences are discussed.

scholarly journals Effects of the Thickness of N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 966
Author(s):  
Sang-Geon Park ◽  
Won Jae Lee ◽  
Min Jong Song ◽  
Johngeon Shin ◽  
Tae Wan Kim
Keyword(s):  
Current Efficiency ◽  
Current Density ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Optical Characteristics ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light

We examined the electro-optical characteristics of organic light emitting diodes according to the N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (TPD) thicknesses. The thicknesses of TPD were varied from 5 nm to 50 nm. The current density of the device with a TPD thickness of 5 nm was 8.94 times higher than that with a thickness of 50 nm at a driving voltage of 10 V. According to the conduction–current characteristics of conductors, the current densities improved with a decreasing TPD thickness. Different from the current density–voltage characteristics, the current efficiency–current density characteristics showed an improved efficiency with a 50 nm TPD thickness. The current efficiencies of a device with a 5 nm TPD thickness at a driving voltage of 10 V was 0.148 and at a 50 nm TPD thickness 0.993 cd/A, which was 6.7 times higher than the 5 nm TPD thickness. These results indicated that hole transport in Organic Light-Emitting Diode (OLED) devices were more efficient with thin 5 nm TPD than with thick 50 nm TPD, while electron transport was more efficient with thick 50 nm TPD, which caused conflicting results in the current efficiency-current density and current density-voltage characteristics according to TPD thicknesses.

Superb lifetime of blue organic light-emitting diodes through engineering interface carrier blocking layers and adjusting electron leakage and an unusual efficiency variation at low electric field

2018 ◽  
Vol 6 (31) ◽  
pp. 8472-8478 ◽  
Author(s):  
Taekyung Kim ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee
Keyword(s):  
Electric Field ◽  
Electron Density ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Electron Leakage ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Long Lifetime

An extremely long lifetime blue organic light-emitting diode (OLED) was developed through managing the electron density and an S-shaped variation of efficiency in blue fluorescent organic light-emitting diodes (FOLEDs) using carrier blocking layers and systematically analyzed in conjunction with the efficiency–lifetime interrelationship.

scholarly journals All solution-processed ITO free flexible organic light-emitting diodes

2020 ◽  
Vol 1 (8) ◽  
pp. 2755-2762
Author(s):  
Yolande Murat ◽  
Karlis Petersons ◽  
Deepak Lanka ◽  
Lars Lindvold ◽  
Leif Yde ◽  
...  
Keyword(s):  
Contact Angle ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Solution Process ◽  
Organic Light Emitting Diodes ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

A top-emitting organic light-emitting diode is fabricated by a solution-process exclusively, using a PEDOT:PSS formulation with a low contact angle.

Sign in / Sign up

Export Citation Format

Share Document