Perovskite LEDs: high efficiency and high brightness (Conference Presentation)

Author(s):  
Jianpu Wang
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.


2018 ◽  
Vol 6 (40) ◽  
pp. 10793-10803 ◽  
Author(s):  
Shian Ying ◽  
Dezhi Yang ◽  
Xianfeng Qiao ◽  
Yanfeng Dai ◽  
Qian Sun ◽  
...  

High-performance WOLEDs realizing high efficiency and low efficiency roll-off simultaneously were achieved by strategically managing triplet excitons in the emission layer.


2019 ◽  
Vol 7 (46) ◽  
pp. 14709-14716 ◽  
Author(s):  
Seokwoo Kang ◽  
Hyocheol Jung ◽  
Hayoon Lee ◽  
Sunwoo Park ◽  
Joonghan Kim ◽  
...  

Three blue fluorescent materials were newly synthesized. A device doped with p-TPA-AP-TPA displayed a very high efficiency of 9.14 cd A−1 and an EQE of 8.38% at a high luminance of 5000 cd m−2.


2017 ◽  
Author(s):  
A. K. Hansen ◽  
M. Christensen ◽  
D. Noordegraaf ◽  
P. Heist ◽  
E. Papastathopoulos ◽  
...  

2004 ◽  
Vol 846 ◽  
Author(s):  
Heh-Lung Huang ◽  
Kou-Hui Shen ◽  
Miao-Cai Jhu ◽  
Mei-Rurng Tseng ◽  
Jia-Ming Liu

ABSTRACTWe investigated and synthesized different orientation and substituted group of the thieno-pyridine framework organo-iridium complexes (PO-01, PO-02, PO-03). These materials exhibited yellow light. Fabrication of these emissive phosphorescent dopants with the device configuration of ITO/ NPB/ CBP: Ir-complex (4–6%) /BCP/Alq3/LiF/Al showed the EL emitting peak from 532nm to 564nm. The electroluminescent efficiencies of the devices were from 9.62 lm/W to 30.41 lm/W and maximum brightness was all above 7000 cd/m2. We demonstrated high-efficiency, high-brightness and saturated yellow Ir-complex phosphorescent materials for OLED.


Author(s):  
Yu-Jen Chen ◽  
Wen-Ching Yang ◽  
Chin-Sien Moo ◽  
Yao-Ching Hsieh

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