Pyridine-Incorporated Dihexylquaterthiophene: A Novel Blue Emitter for Organic Light Emitting Diodes (OLEDs)

2012 ◽  
Vol 65 (9) ◽  
pp. 1244 ◽  
Author(s):  
Prashant Sonar ◽  
Sonsoles Garcia Santamaria ◽  
Ting Ting Lin ◽  
Alan Sellinger ◽  
Henk Bolink
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
High Yield ◽  
Device Performance ◽  
Host Matrix ◽  
Maximum Brightness ◽  
Light Emitting ◽  
Organic Light ◽  
Processing Techniques

The synthesis and characterisation of 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) and its use as a blue emitter in organic light emitting diodes (OLEDs) is reported. Th4PY was synthesised in high yield using a straightforward Suzuki coupling route with commercially available starting materials. As Th4PY is both soluble and has low molecular weight, blue OLEDs were fabricated using both spin-coating and vacuum deposition thin film processing techniques to study the effect of processing on device performance. OLED devices using a spin-coated layer consisting of 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a host matrix together with Th4PY as emitter exhibited highly efficient sky-blue emission with a low turn-on voltage of 3 V, a maximum brightness close to 15000 cd m–2 at 8 V, and a maximum luminous efficiency of 7.4 cd A–1 (6.3 lm W–1) with CIE coordinates of x = 0.212, y = 0.320. The device performance characteristics are compared using various matrices and processing techniques. The promising sky-blue OLED performance, solution processability, and ambient stability make Th4PY a promising blue emitter for application in OLEDs.

Highly efficient organic–inorganic electroluminescence materials for solution-processed blue organic light-emitting diodes

2016 ◽  
Vol 4 (27) ◽  
pp. 6461-6465 ◽  
Author(s):  
Chih-Chia Cheng ◽  
Yu-Lin Chu ◽  
Chih-Wei Chu ◽  
Duu-Jong Lee
Keyword(s):  
High Purity ◽  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
Device Performance ◽  
Solution Processed ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light ◽  
Emission Color

A novel organic–inorganic electroluminescent macromer as an efficient emissive-layer in OLED devices exhibits excellent device performance with high-purity blue emission color.

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.

scholarly journals Efficient Exciplex-Based Deep-Blue Organic Light-Emitting Diodes Employing a Bis(4-fluorophenyl)amine-Substituted Heptazine Acceptor

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5568
Author(s):  
Jie Li ◽  
Heqi Gong ◽  
Jincheng Zhang ◽  
Hui Liu ◽  
Li Tao ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Deep Blue ◽  
Photoluminescence Quantum Yield ◽  
Organic Light ◽  
High Maximum ◽  
Exciplex Emission ◽  
Amine Groups

The realization of a deep-blue-emitting exciplex system is a herculean task in the field of organic light-emitting diodes (OLEDs) on account of a large red-shifted and broadened exciplex emission spectrum in comparison to those of the corresponding single compounds. Herein, 2,5,8-tris(di(4-fluorophenyl)amine)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3FDPA) was designed as an electron acceptor by integrating three bis(4-fluorophenyl)amine groups into a heptazine core, while 1,3-di(9H-carbazol-9-yl)benzene (mCP) possessing two electron-donating carbazole moieties was chosen as the electron donor. Excitingly, the exciplex system of 8 wt% HAP-3FDPA:mCP exhibited deep-blue emission and a high photoluminescence quantum yield of 53.2%. More importantly, an OLED containing this exciplex system as an emitting layer showed deep-blue emission with Commission Internationale de l’Eclairage coordinates of (0.16, 0.12), a peak luminance of 15,148 cd m−2, and a rather high maximum external quantum efficiency of 10.2% along with a low roll-off. This study not only reports an efficient exciplex-based deep-blue emitter but also presents a feasible pathway to construct highly efficient deep-blue OLEDs based on exciplex systems.

Dibenzo[f,h]furo[2,3-b]quinoxaline-based molecule scaffold as deep blue fluorescence materials for organic light-emitting diodes

2021 ◽  
Author(s):  
XinYe Wang ◽  
Yuan Wu ◽  
ChuanMing Wu ◽  
Yixiang Li ◽  
Dongdong Wang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
Molecular Scaffolds ◽  
Blue Fluorescence ◽  
Light Emitting ◽  
Highly Efficient ◽  
Deep Blue ◽  
Organic Light

Two novel molecular scaffolds, dibenzo[f,h]furo[2,3-b]quinoxaline (diBFQ) and its derivative, 3,6-bis(4-isopropylphenyls)-11-phenyldibenzo[f,h]furo[2,3-b]quinoxaline (dP-diBFQ), and furo[2',3':5,6]pyrazino[2,3-f][1,10]phenanthroline (FPPhen), were designed and syn-thesized for highly efficient pure and deep blue emission. The unsubstituted molecule scaffold...

High-Performance Solution Processed Red Hyperfluorescent OLEDs Based on Cibalackrot

2022 ◽  
Author(s):  
Nicholle R. Wallwork ◽  
Masashi Mamada ◽  
Atul Shukla ◽  
Sarah K. M. McGregor ◽  
Chihaya Adachi ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Device Performance ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light

Hyperfluorescent organic light-emitting diodes (OLEDs) has allowed remarkable device performances to be achieved using fluorescent emitters. Superior device performance has been realised using thermally evaporated emissive layers. However, for future...

Tetraphenylpyrazine decorated 1,3-di(9H-carbazol-9-yl)benzene (mCP): a new AIE-active host with enhanced performance in organic light-emitting diodes

2019 ◽  
Vol 7 (36) ◽  
pp. 11160-11166
Author(s):  
Jiali Guo ◽  
Lingxiang Pan ◽  
Bo Song ◽  
Jiabao Gu ◽  
Jiajie Zeng ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Device Performance ◽  
Light Emitting ◽  
Organic Light

Decorating a conventional mCP host with a tetraphenylpyrazine moiety generates a new AIE-active host, from which better device performance was realized.

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