17.2: Invited Paper: Pure Delayed Fluorescence Organic Light‐Emitting Diodes Featuring Low Driving Voltage and High Brightness

2021 ◽  
Vol 52 (S2) ◽  
pp. 229-229
Author(s):  
Feng-Ming Xie ◽  
Shi-Jie Zou ◽  
Yan-Qing Li ◽  
Jian-Xin Tang
2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniel Ping-Kuen Tsang ◽  
Toshinori Matsushima ◽  
Chihaya Adachi

Abstract Organic light-emitting diodes (OLEDs) under constant current operation suffer from a decrease of luminance accompanied by an increase of driving voltage. We report a way to greatly improve the stability of OLEDs having a green emitter exhibiting thermally activated delayed fluorescence (TADF), (4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl) isophthalonitrile (4CzIPN), by introducing ultrathin (1 to 3 nm) interlayers of 8-hydroxyquinolinato lithium (Liq) between hole-blocking layer and its surrounding emissive and electron-transport layers. Under constant current operation starting at a luminescence of 1,000 cd/m2, the time to reach 90% of initial luminance (LT90) increased eight times, resulting in LT90 = 1,380 hours after insertion of the interlayers. Combining this new concept and mixed host system, LT95 was further extended to 1315 hours that is 16 times of reference device. This is the best value reported for TADF-based OLEDs and is comparable to the operational lifetimes of well-established phosphorescence-based OLEDs. Thermally stimulated current measurements showed that the number of deep charge traps was reduced with the insertion of the ultrathin Liq interlayer, indicating that reducing the number of deep traps is important for improving the operational lifetime and that exciton-polaron annihilation may be a source of the device degradation.


2007 ◽  
Vol 91 (1) ◽  
pp. 011113 ◽  
Author(s):  
Dong-Seok Leem ◽  
Hyung-Dol Park ◽  
Jae-Wook Kang ◽  
Jae-Hyun Lee ◽  
Ji Whan Kim ◽  
...  

Author(s):  
Sung Yong Byun ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee

The effect of lowest unoccupied molecular orbital (LUMO) management of high triplet energy electron transport type hosts on the device performance of blue thermally-activated delayed fluorescence (TADF) organic light-emitting diodes...


Author(s):  
Jingwen Xu ◽  
Xing Wu ◽  
Jingjing Guo ◽  
Zujin Zhao ◽  
Ben Zhong Tang

In comparison with green and red OLEDs, which have well developed with satisfactory electroluminescence (EL) performances, high-efficiency blue OLEDs still need further exploration. Herein, by reasonably strengthening the rigidity of...


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