Polymeric light emitting properties and structural relationships of fluorene-based conjugated copolymers containing various hole transporting derivatives

2007 ◽  
Vol 8 (2-3) ◽  
pp. 272-285 ◽  
Author(s):  
Jong-Hwa Park ◽  
Nam Sung Cho ◽  
Young Kwan Jung ◽  
Hoon-Je Cho ◽  
Hong-Ku Shim ◽  
...  
Keyword(s):  
Light Emitting ◽  
Structural Relationships ◽  
Hole Transporting ◽  
Conjugated Copolymers

Controlled Injection of Holes into ALQ3 Based Oleds by Means of An Oxidized Transport Layer

2001 ◽  
Vol 708 ◽  
Author(s):  
Mathew K. Mathai ◽  
Keith A. Higginson ◽  
Bing R. Hsieh ◽  
Fotios Papadimitrakopoulos
Keyword(s):  
Indium Tin Oxide ◽  
Oxidative Degradation ◽  
Transport Layer ◽  
Hole Injection ◽  
Carrier Injection ◽  
Salt Loading ◽  
Light Emitting ◽  
Hole Transporting ◽  
Intrinsic Degradation ◽  
Variable Conductivity

ABSTRACTIn this paper we report a method for tuning the extent of hole injection into the active light emitting tris- (8-hydroxyquinoline) aluminum (Alq3) layer in organic light emitting diodes (OLEDs). This is made possible by modifying the indium tin oxide (ITO) anode with an oxidized transport layer (OTL) comprising a hole transporting polycarbonate of N,N'-bis(3-hydroxymethyl)-N,N'-bis(phenyl) benzidine and diethylene glycol (PC-TPB-DEG) doped with varying concentrations of antimonium hexafluoride salt of N,N,N',N'-tetra-p-tolyl-4,4'-biphenyldiamine (TMTPD+ SbF6-). The conductivity of the OTL can be changed over three orders of magnitude depending on salt loading. The analysis of hole and electron current variations in these devices indicates that optimizing the conductivity of the OTL enables the modulation of hole injection into the Alq3 layer. The bipolar charge transport properties for OLEDs in which the interfacial carrier injection barriers have been minimized, are governed by the conductivities of the respective layers and in this case it is shown that the variable conductivity of the OTL does allow for better control of the same. Accordingly, varying the concentration of holes in the device indicates that beyond an optimum concentration of holes, further hole injection results in the formation of light quenching cationic species and the initiation of oxidative degradation processes in the Alq3 layer, thus accelerating the intrinsic degradation of these devices. The variable conductivity of the OTL can hence be used to minimize the occurrence of these processes.

scholarly journals High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Vasilopoulou ◽  
Abd. Rashid bin Mohd Yusoff ◽  
Matyas Daboczi ◽  
Julio Conforto ◽  
Anderson Emanuel Ximim Gavim ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
High Mobility ◽  
Organic Light Emitting Diodes ◽  
Triplet Energy ◽  
Material Interface ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Hole Transporting

AbstractBlue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light-emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency (EQE) of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m−2. Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures.

An Efficient Hole Transporting Polymer for Quantum Dot Light‐Emitting Diodes

2021 ◽  
pp. 2100731
Author(s):  
Wenhai Wu ◽  
Zhao Chen ◽  
Yunfeng Zhan ◽  
Bochen Liu ◽  
Weidong Song ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Hole Transporting

Bis(4-diphenylaminophenyl)carbazole end-capped fluorene as solution-processed deep-blue light-emitting and hole-transporting materials for electroluminescent devices

2012 ◽  
Vol 53 (28) ◽  
pp. 3615-3618 ◽  
Author(s):  
Daungratchaneekron Meunmart ◽  
Narid Prachumrak ◽  
Tinnagon Keawin ◽  
Siriporn Jungsuttiwong ◽  
Taweesak Sudyoadsuk ◽  
...  
Keyword(s):  
Blue Light ◽  
Solution Processed ◽  
Electroluminescent Devices ◽  
Light Emitting ◽  
Deep Blue ◽  
Hole Transporting ◽  
Hole Transporting Materials

Low driving voltage and high stability organic light-emitting diodes with rhenium oxide-doped hole transporting layer

2007 ◽  
Vol 91 (1) ◽  
pp. 011113 ◽  
Author(s):  
Dong-Seok Leem ◽  
Hyung-Dol Park ◽  
Jae-Wook Kang ◽  
Jae-Hyun Lee ◽  
Ji Whan Kim ◽  
...  
Keyword(s):  
High Stability ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Rhenium Oxide ◽  
Light Emitting ◽  
Organic Light ◽  
Hole Transporting

Influence of hole transporting material on device performance in organic light-emitting diode

2000 ◽  
Vol 363 (1-2) ◽  
pp. 290-293 ◽  
Author(s):  
Shizuo Tokito ◽  
Koji Noda ◽  
Kou Shimada ◽  
Shin-ichiro Inoue ◽  
Makoto Kimura ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Device Performance ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Hole Transporting ◽  
Hole Transporting Material

A High Tg Carbazole-Based Hole-Transporting Material for Organic Light-Emitting Devices

2005 ◽  
Vol 17 (5) ◽  
pp. 1208-1212 ◽  
Author(s):  
Jiuyan Li ◽  
Di Liu ◽  
Yanqing Li ◽  
Chun-Sing Lee ◽  
Hoi-Lun Kwong ◽  
...  
Keyword(s):  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Hole Transporting ◽  
Organic Light Emitting Devices ◽  
Hole Transporting Material

Solution-processable highly efficient deep-red and orange organic light-emitting diodes based on multi-functional Ir(iii) complexes

2017 ◽  
Vol 5 (38) ◽  
pp. 10029-10038 ◽  
Author(s):  
Woosum Cho ◽  
Ganguri Sarada ◽  
Athithan Maheshwaran ◽  
Yeong-Soon Gal ◽  
Yeonsig Nam ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Improve Performance ◽  
Light Emitting ◽  
Highly Efficient ◽  
Organic Light ◽  
Hole Transporting ◽  
Solution Processable

Linking the hole transporting/electron transporting functional moieties to the Ir(iii) complex is a key strategy to improve performance of PhOLEDs.

Improve the Efficiency of White Organic Light-Emitting Devices Using Double-Doped System

2010 ◽  
Vol 152-153 ◽  
pp. 687-690
Author(s):  
Gui Ying Ding ◽  
Wen Long Jiang ◽  
Guang De Wang ◽  
Qiang Han ◽  
Xi Chang
Keyword(s):  
Current Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Maximum Current ◽  
Hole Transporting ◽  
White Oleds ◽  
Organic Light Emitting Devices ◽  
20 Nm ◽  
White Oled

The doped and non-doped white Organic light-emitting devices (OLEDs) were fabricated, using strong yellow emitting and hole-transporting ability of TPAHQZn. When the white OLED is a double-doped structure, greatly enhanced the efficiency of the device. The double-doped white device were fabricated as follows: ITO/2T-NATA (17 nm)/ CBP: 30% TPAHQZn: 8% Ir(ppy)3 (25 nm)/ NPBX (15 nm)/BCP(8nm)/TPBi: 10% Ir(ppy)3 (15nm)/Alq3 (20 nm)/LiF (1.3 nm)/Al. The double-doped white OLEDs were obtained with Commission International de L’Eclairage coordinates of (0.29,0.28) at 17 V, the maximum current efficiency increaed four times that double-doped white device of 4.12cd/A(8V) than non-doped of 1.03 cd/A (10V) .

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