Solution-processable bipolar host materials composed of fluorenyl, carbazolyl and 1,3,4-oxadiazolyl derivatives: synthesis and application in phosphorescent organic light-emitting diodes

2016 ◽  
Vol 4 (22) ◽  
pp. 5091-5101 ◽  
Author(s):  
Tso-Hsing Fan ◽  
Yun Chen
Keyword(s):  
Spin Coating ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Coating Process ◽  
Emission Layer ◽  
Light Emitting ◽  
Spin Coating Process ◽  
Organic Light ◽  
Host Materials ◽  
Solution Processable

Two new bipolar compounds were synthesized and applied as hosts for phosphorescent organic light-emitting diodes, using a spin-coating process to cast a homogeneous emission layer. Their device performances outperform conventional host poly(9-vinylcarbazole).

Carbazole/oligofluorene end-capped hexanes: solution-processable host materials for phosphorescent organic light-emitting diodes

2017 ◽  
Vol 5 (18) ◽  
pp. 4442-4447 ◽  
Author(s):  
Huanhuan Li ◽  
Ye Tao ◽  
Runfeng Chen ◽  
Guohua Xie ◽  
Chao Zheng ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
New Method ◽  
Light Emitting ◽  
Organic Light ◽  
Host Materials ◽  
Solution Processable ◽  
End Capping

High-performance solution-processable host materials for electrophosphorescent devices have been developed via a new method of aromatic double end-capping alkylization.

Highly efficient bipolar host materials towards solution-processable blue and green thermally activated delayed fluorescence organic light emitting diodes

2018 ◽  
Vol 6 (37) ◽  
pp. 10000-10009 ◽  
Author(s):  
Mallesham Godumala ◽  
Suna Choi ◽  
Seong Keun Kim ◽  
Si Woo Kim ◽  
Jang Hyuk Kwon ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Device Performance ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Host Materials ◽  
Solution Processable

Simple structured bipolar host materials boosted the device performance of solution processable blue and green thermally activated delayed fluorescence organic light emitting diodes.

scholarly journals Solution-Processed Efficient Blue Phosphorescent Organic Light-Emitting Diodes (PHOLEDs) Enabled by Hole-Transport Material Incorporated Single Emission Layer

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 554
Author(s):  
Taeshik Earmme
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Emission Layer ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light ◽  
Single Emission ◽  
Blue Phosphorescent

Solution-processed blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a single emission layer with small-molecule hole-transport materials (HTMs) are demonstrated. Various HTMs have been readily incorporated by solution-processing to enhance hole-transport properties of the polymer-based emission layer. Poly(N-vinylcarbazole) (PVK)-based blue emission layer with iridium(III) bis(4,6-(di-fluorophenyl)pyridinato-N,C2′)picolinate (FIrpic) triplet emitter blended with solution-processed 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) gave luminous efficiency of 21.1 cd/A at a brightness of 6220 cd/m2 with an external quantum efficiency (EQE) of 10.6%. Blue PHOLEDs with solution-incorporated HTMs turned out to be 50% more efficient compared to the reference device without HTMs. The high hole mobility, high triplet energy of HTM, and favorable energy transfer between HTM blended PVK host and FIrpic blue dopant were found to be important factors for achieving high device performance. The results are instructive to design and/or select proper hole-transport materials in solution-processed single emission layer.

Four color stacked white organic light-emitting diodes utilizing the concept of triplet harvesting

2011 ◽  
Vol 1286 ◽  
Author(s):  
Th. C. Rosenow ◽  
S. Olthof ◽  
S. Reineke ◽  
B. Lüssem ◽  
K. Leo
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
Light Sources ◽  
Emission Layer ◽  
Light Emitting ◽  
Organic Light ◽  
Blue Emitters ◽  
Color Rendering ◽  
Triplet Harvesting

ABSTRACTOrganic light-emitting diodes (OLEDs) are developing into a competitive alternative to conventional light sources. Nevertheless, OLEDs need further improvement in terms of efficiency and color rendering for lighting applications. Fluorescent blue emitters allow deep blue emission and high stability, while phosphorescent blue emitter still suffer from insufficient stability. The concept of triplet harvesting is the key for achieving internal quantum efficiencies up to 100 % and simultaneously benefiting from the advantages of fluorescent blue emitters. Here, we present a stacked OLED consisting of two units comprising four different emitters in total. The first unit takes advantage of the concept of triplet harvesting and combines the light emission of a fluorescent blue and a phosphorescent red emitter. The second unit emits light from a single emission layer consisting of a matrix doped with phosphorescent green and yellow emitters. With this approach, we reach white color coordinates close to the standard illuminant A and a color rendering index of above 75. The presented devices are characterized by high luminous efficacies of above 30 lm/W on standard glass substrates without outcoupling enhancement.

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