Boosting reverse intersystem crossing by increasing donors in triarylboron/phenoxazine hybrids: TADF emitters for high-performance solution-processed OLEDs

2016 ◽  
Vol 4 (20) ◽  
pp. 4402-4407 ◽  
Author(s):  
Yuan Liu ◽  
Guohua Xie ◽  
Kailong Wu ◽  
Zhenghui Luo ◽  
Tao Zhou ◽  
...  

A triarylboron/phenoxazine hybrid TADF emitter exhibits efficient reverse intersystem crossing and the device achieves a maximum external quantum efficiency of 13.9%.

2017 ◽  
Vol 5 (23) ◽  
pp. 5749-5756 ◽  
Author(s):  
Lingcheng Chen ◽  
Shumeng Wang ◽  
Zhimin Yan ◽  
Junqiao Ding ◽  
Lixiang Wang

By fully encapsulating the heteroleptic red Ir complex with carbazole dendrons, solution-processed nondoped electrophosphorescent devices reveal over 10% EQE.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Fatemeh Maasoumi ◽  
Ross D. Jansen-van Vuuren ◽  
Paul E. Shaw ◽  
Emma V. Puttock ◽  
Ravi Chandra Raju Nagiri ◽  
...  

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  

<p> Colloidal quantum wells (CQWs) are regarded as a new, highly promising class of optoelectronic materials thanks to their unique excitonic characteristics of high extinction coefficient and ultranarrow emission bandwidth. Although the exploration of CQWs in light-emitting diodes (LEDs) is impressive, the performance of CQW-LEDs lags far behind compared with other types of LEDs (e.g., organic LEDs, colloidal quantum-dot LEDs, and perovskite LEDs). Herein, for the first time, the authors show high-efficiency CQW-LEDs reaching close to the theoretical limit. A key factor for this high performance is the exploitation of hot-injection shell (HIS) growth of CQWs, which enables a near-unity photoluminescence quantum yield (PLQY), reduces nonradiative channels, ensures smooth films and enhances the stability. Remarkably, the PLQY remains 95% in solution and 87% in film despite rigorous cleaning. Through systematically understanding their shape-, composition- and device- engineering, the CQW-LEDs using CdSe/Cd<sub>0.25</sub>Zn<sub>0.75</sub>S core/HIS CQWs exhibit a maximum external quantum efficiency of 19.2%. Additionally, a high luminance of 23,490 cd m<sup>-2</sup>, extremely saturated red color with the Commission Internationale de L’Eclairage coordinates of (0.715, 0.283) and stable emission are obtained. The findings indicate that HIS grown CQWs enable high-performance solution-processed LEDs, which may pave the path for CQW-based display and lighting technologies.</p>


Author(s):  
Xiaokang Li ◽  
Wenxing Liu ◽  
Kai Chen ◽  
Ruixia Wu ◽  
Guo-Jun Liu ◽  
...  

Abstract In this work, we have experimentally demonstrated the efficacy of micro-cavity effect in realizing high-performance top-emitting organic light-emitting diodes (TEOLEDs). By optimizing the thickness of top Yb/Ag electrode and cavity length, highly efficient green TEOLED with external quantum efficiency as high as 38% was achieved. A strong dependence of electroluminescent (EL) performances and spectrum on cavity length was observed, and there was also a significant angle dependence of EL spectrum. Ultimately, ultra-high current efficiency up to 161.17 cd/A (3.2 V) was obtained by the device with emission peak at 552 nm, which is 35 nm longer than the intrinsic emission peak (517 nm) of utilized green emitter. Interestingly, this device displayed narrow emission with full-width at half-maximum (FWHM) of less than 20 nm, which was obtained by increasing the Ag layer thickness.


2018 ◽  
Vol 6 (20) ◽  
pp. 5363-5368 ◽  
Author(s):  
Ji Han Kim ◽  
Dong Ryun Lee ◽  
Si Hyun Han ◽  
Jun Yeob Lee

Highly efficient red thermally activated delayed fluorescence organic light-emitting diodes were developed using a reverse intersystem crossing activating host derived from phenylcarbazole and pyridofuropyridine.


2020 ◽  
Vol 8 (47) ◽  
pp. 17009-17015
Author(s):  
Indu Bala ◽  
Rohit Ashok Kumar Yadav ◽  
Manisha Devi ◽  
Joydip De ◽  
Nitya Singh ◽  
...  

Benzothiadiazole-based donor–acceptor emitters with hybrid local and charge transfer state exhibit high external quantum efficiency in solution-processed green OLEDs.


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