Efficient triplet harvesting by fluorescent molecules through exciplexes for high efficiency organic light-emitting diodes

2013 ◽  
Vol 102 (15) ◽  
pp. 153306 ◽  
Author(s):  
Young-Seo Park ◽  
Kwon-Hyeon Kim ◽  
Jang-Joo Kim
2021 ◽  
Vol 15 (3) ◽  
pp. 208-215 ◽  
Author(s):  
Soon Ok Jeon ◽  
Kyung Hyung Lee ◽  
Jong Soo Kim ◽  
Soo-Ghang Ihn ◽  
Yeon Sook Chung ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Vasilopoulou ◽  
Abd. Rashid bin Mohd Yusoff ◽  
Matyas Daboczi ◽  
Julio Conforto ◽  
Anderson Emanuel Ximim Gavim ◽  
...  

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.


2011 ◽  
Vol 1286 ◽  
Author(s):  
Th. C. Rosenow ◽  
S. Olthof ◽  
S. Reineke ◽  
B. Lüssem ◽  
K. Leo

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.


2011 ◽  
Vol 12 (5) ◽  
pp. 843-850 ◽  
Author(s):  
Chao Cai ◽  
Shi-Jian Su ◽  
Takayuki Chiba ◽  
Hisahiro Sasabe ◽  
Yong-Jin Pu ◽  
...  

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...


2018 ◽  
Vol 30 (50) ◽  
pp. 1804231 ◽  
Author(s):  
Amlan K. Pal ◽  
Simonas Krotkus ◽  
Mattia Fontani ◽  
Campbell F. R. Mackenzie ◽  
David B. Cordes ◽  
...  

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