Tetraphenylmethane-Based 1,3,4-Oxadiazole as Electron Transporting Materials in Organic Light-Emitting Devices

1999 ◽  
Vol 598 ◽  
Author(s):  
Chin-Ti Chen ◽  
Tzu-Yao J. Lin ◽  
Hsiu-Chih Yeh ◽  
Li-Hsin Jan ◽  
Easwaramoorthy Balasubramaniam ◽  
...  
Keyword(s):  
Glass Phase ◽  
Molecular Design ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Current Voltage ◽  
Electron Transporting Layer ◽  
Current Voltage Characteristics

ABSTRACTA series of tetrahedral tetramers of 2,5-diphenyl substituted 1,3,4-oxadiazole compounds were synthesized and characterized for electron-transporting layer (ETL) in organic light-emitting diode (OLED). The multiple-branch design of the oxadiazole tetramers intends to increase the melting temperature and to generate glass phase of the low molar mass derivative such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD). We observed temperatures of the glass phase transition for the oxadiazole tetramer with appropriate peripheral substituents, indicative of amorphous characteristics of the molecule in spite of highly symmetrical molecular framework. The luminescence-current-voltage characteristics of multilayer OLED devices containing the oxadiazole tetramer or PBD as ETL were examined to evaluate the efficiency of our multiple-branch molecular design.

High Brightness White Organic Light Emitting Devices Employing Phosphorescent Iridium Complex as RGB Dopants

2007 ◽  
Vol 364-366 ◽  
pp. 1072-1076
Author(s):  
Rui Li Song ◽  
Yu Duan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Iridium Complex ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Color Mixing ◽  
Coordinate Changes ◽  
Cie Chromaticity

An efficient phosphorescent white organic light-emitting diode (WOLED) was realized by using a bright blue-emitting layer, iridium (III) bis [(4, 6-di-fluoropheny)-pyridinato-N, C2’] picolinate doped 4.4’-bis (9-carbazolyl)-2, 2’-dimethyl-biphenyl, together with tris (2- Phenylpyridine) iridium and bis (1-phenyl-isoquinoline) acetylacetonate iridium (III) were codoped into 4,4’-N,N’-dicarbazole-biphenyl layer to provide blue, green, and red emission for color mixing. The device emission color was controlled by varying dopant concentrations and the thickness of blue and green-red layers as well as tuning the thickness of exciton-blocking layer. The maximum luminance and power efficiency of the WOLED were 37100cd/m2 at 17 V and 7.37lm/W at 5V, respectively. The Commission Internationale de 1’Eclairage (CIE) chromaticity coordinate changes from (0.41, 0.42) to (0.37, 0.39) when the luminance rangeed from 1000cd/m2 to 30000cd/m2.

Tri-Metal Layered Semitransparent Electrode for Red Phosphorescent Organic Light-Emitting Diodes

2015 ◽  
Vol 15 (10) ◽  
pp. 8144-8148 ◽  
Author(s):  
Jae Woo Lee ◽  
Ho Won Lee ◽  
Song Eun Lee ◽  
Hyung Jin Yang ◽  
Sung Kyu Lee ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Glass Substrate ◽  
Light Emitting Diode ◽  
Metal Layer ◽  
Flexible Substrate ◽  
Flexible Display ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light

In this paper, we fabricated tri-metal layered thin film semitransparent electrodes consisting of a thin conductive metal layer, sandwiched between two nickel layers. An equal red phosphorescent organic light-emitting diode (PHOLED) structure was deposited on the anodes of indium tin oxide (ITO) and three types of tri-metal layers (Ni/Al/Ni, Ni/Cu/Ni, and Ni/Ag/Ni, thickness of 3/7/3 nm in common) on a glass substrate. The optical and electrical performances of the device using Ni/Ag/Ni were improved more than the performances of the other devices due to the micro-cavity effect in accordance with the various electrode characteristics. Moreover, we fabricated the same red PHOLED structures on a flexible substrate, as a consequence, showed competitive emission characteristics compared to the devices fabricated on a glass substrate. Therefore, this study could succeed to additional research on flexible display panel and light-emitting devices with ITO-free electrodes.

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.

Carbon Quantum Dot as Electron Transporting Layer in Organic Light Emitting Diode

2019 ◽  
Vol 4 (25) ◽  
pp. 7450-7454 ◽  
Author(s):  
Md. Bayazeed Alam ◽  
Kanchan Yadav ◽  
Devyani Shukla ◽  
Ritu Srivastava ◽  
Jayeeta Lahiri ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Carbon Quantum Dot ◽  
Organic Light ◽  
Electron Transporting Layer

scholarly journals Carbon Dots as A Sustainable New Platform for Organic Light Emitting Diode

2020 ◽  
Author(s):  
Paola Lagonegro ◽  
Umberto Giovanella ◽  
Mariacecilia Pasini
Keyword(s):  
Carbon Dots ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Research Outcomes ◽  
Organic Light ◽  
The Impact ◽  
Organic Resources ◽  
Safe By Design

In the last 10 years, carbon dots (CDs) synthesized from renewable organic resources have been gathered a considerable amount of attention in different fields for their peculiar photoluminescent properties. Moreover, the synthesis of CDs fully responds to the principles of the circular chemistry and the concept of safe-by-design. This review will focus on the different strategies for the incorporation of CDs in organic light-emitting devices (OLEDs) and on the study of the impact of CDs properties on the OLEDs performance. The main current research outcomes and highlights are summarized to guide users towards the fully exploitation of use these materials in optoelectronic applications.

Highly soluble fluorous alkyl ether-tagged imaging materials for the photo-patterning of organic light-emitting devices

2017 ◽  
Vol 5 (4) ◽  
pp. 926-930 ◽  
Author(s):  
Jongchan Son ◽  
Hyun-Taek Oh ◽  
O Jun Kwon ◽  
Jong-Min Lim ◽  
Heeyoung Jung ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Alkyl Ether ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Organic Light Emitting Devices

A photolithographic patterning scheme for organic light-emitting diode (OLED) pixels was proposed, requiring highly soluble imaging materials in fluorous solvents.

Electrical Behavior I-V Theoretical-Experimental OLEDS

2014 ◽  
Vol 1613 ◽  
pp. 121-126
Author(s):  
José M. Burgoa ◽  
Cecilia González-Medina ◽  
Ramón Gómez-Aguilar ◽  
Jaime Ortiz-López
Keyword(s):  
Light Emitting Diode ◽  
Hole Injection ◽  
Software Environment ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Current Voltage ◽  
Polymer Semiconductor ◽  
Current Voltage Characteristics ◽  
Derivatives Of ◽  
Magnitude Difference

ABSTRACTWe develop a program (within MATLAB software environment) to numerically simulate current-voltage characteristics of a bilayer organic light-emitting diode (OLED). The program is based on the Poole-Frenkel and Schottky continuous quantum models which take into account the geometry of thin films and their emission parameters in the calculation of charge carrier and current density in organic materials. Simulations are performed for OLEDs with A/EML/C and A/HIL/EML/C architectures where A=anode, HIL=hole injection layer, EML=emissive layer and C=cathode. For EML we assume MEH-PPV and MDMO-PPV derivatives of poly-para-phenylene-vinylene (PPV) polymer semiconductor, and for HIL we use PEDOT:PSS. The results of simulation are compared with experimental results obtained from actual OLED devices constructed in our laboratory. For comparison we also use the commercial software SimOLED to simulate the devices under similar architectures. We find in general a fair agreement between the simulated and measured behavior except for a few orders of magnitude difference in the current.

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