New conjugated electroluminescent triphenylamine-containing polymers with side-chain pyridin-2-ylimidazo[1,5-a]pyridine groups for polymer light-emitting diodes

2013 ◽  
Vol 450 (2) ◽  
pp. 165-172 ◽  
Author(s):  
M. L. Keshtov ◽  
Fang-Chung Chen ◽  
E. I. Maltsev ◽  
D. V. Marochkin ◽  
V. S. Kochurov ◽  
...  
2008 ◽  
Vol 8 (9) ◽  
pp. 4846-4850
Author(s):  
Hui Wang ◽  
Jeong-Tak Ryu ◽  
Chao Cao ◽  
Younghwan Kwon

Structurally well-defined copolymers with high solubility were prepared via palladium-catalyzed polycondensation of N-(2-ethylhexyl)-3,6-dibromocarbazole with 2-aryl-5-(4-aminophenyl)-1,3,4-oxadiazole (aryl = phenyl, p-methylphenyl, p-methoxyphenyl). Copolymers consisted of alkylcarbazole groups in the main chain and 1,3,4-oxadiazole pendants in the side chain. The influence of their aryl substituents on physical, optical, band gaps and electroluminescent characteristics of the copolymers was investigated. Both UV-Visible absorption and photoluminescence emission peaks of the copolymers were similar to each other. The band gap energy of the polymers was measured in the range of 2.84∼2.88 eV, and HOMO energy in the range of −5.13∼−5.18 eV. These copolymers were used as hole-transporting layers (HTL) in the light-emitting diodes with Alq3 as an emitting layer. Compared to devices with P-H and P-OCH3 used as HTL, it should be noted that device with P-CH3 used as HTL showed higher luminescence. Maximum luminescence of devices was measured to be 276cd/m2 at 14 V with P-H, 625 cd/m2 at 15 V with P-CH3, and 471 cd/m2 at 14 V with P-OCH3. This might be due to effect of subtle changes in HOMO energy level of polymers with changing substituent groups. Phosphorescent polymer light emitting diodes were also fabricated with an emitting layer consisting of P-CH3 matrix and a red phosphorescent dopant (Ir-PIQCH).


2017 ◽  
Vol 8 (14) ◽  
pp. 2182-2188 ◽  
Author(s):  
Keyan Bai ◽  
Shumeng Wang ◽  
Lei Zhao ◽  
Junqiao Ding ◽  
Lixiang Wang

By fully replacing the alkyloxy side chain with a carbazole, a highly emissive homopolymer P(Cz-SF) is developed for deep-blue PLEDs.


2000 ◽  
Vol 660 ◽  
Author(s):  
Thomas M. Brown ◽  
Ian S. Millard ◽  
David J. Lacey ◽  
Jeremy H. Burroughes ◽  
Richard H. Friend ◽  
...  

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.


2021 ◽  
Vol 9 (36) ◽  
pp. 12068-12072
Author(s):  
Wentao Li ◽  
Jiaxiang Liu ◽  
Baowen Wang ◽  
Siyu Hou ◽  
Xingqiang Lü ◽  
...  

Based on geometrical isomerisation of [Ir(C^N1)(C^N2)((N^O))]-tris-heteroleptic Ir(iii)-complexes, the augmented transition dipole transition (TMD) with a preferential horizontal orientation, which is beneficial for their NIR-phosphorescence, is reported.


2001 ◽  
Vol 79 (2) ◽  
pp. 174-176 ◽  
Author(s):  
T. M. Brown ◽  
R. H. Friend ◽  
I. S. Millard ◽  
D. J. Lacey ◽  
J. H. Burroughes ◽  
...  

2008 ◽  
Vol 20 (4) ◽  
pp. 696-702 ◽  
Author(s):  
H. B. Wu ◽  
J. H. Zou ◽  
F. Liu ◽  
L. Wang ◽  
A. Mikhailovsky ◽  
...  

Materials ◽  
2013 ◽  
Vol 6 (5) ◽  
pp. 1994-2006 ◽  
Author(s):  
Mohammad Rezvani ◽  
Farid Farajollahi ◽  
Alireza Nikfarjam ◽  
Parisa Bakhtiarpour ◽  
Erfan Saydanzad

2007 ◽  
Vol 17 (33) ◽  
pp. 3551 ◽  
Author(s):  
J. Huang ◽  
X. Wang ◽  
A. J. deMello ◽  
J. C. deMello ◽  
D. D. C. Bradley

Sign in / Sign up

Export Citation Format

Share Document