scholarly journals Efficient Exciplex-Based Deep-Blue Organic Light-Emitting Diodes Employing a Bis(4-fluorophenyl)amine-Substituted Heptazine Acceptor

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5568
Author(s):  
Jie Li ◽  
Heqi Gong ◽  
Jincheng Zhang ◽  
Hui Liu ◽  
Li Tao ◽  
...  

The realization of a deep-blue-emitting exciplex system is a herculean task in the field of organic light-emitting diodes (OLEDs) on account of a large red-shifted and broadened exciplex emission spectrum in comparison to those of the corresponding single compounds. Herein, 2,5,8-tris(di(4-fluorophenyl)amine)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3FDPA) was designed as an electron acceptor by integrating three bis(4-fluorophenyl)amine groups into a heptazine core, while 1,3-di(9H-carbazol-9-yl)benzene (mCP) possessing two electron-donating carbazole moieties was chosen as the electron donor. Excitingly, the exciplex system of 8 wt% HAP-3FDPA:mCP exhibited deep-blue emission and a high photoluminescence quantum yield of 53.2%. More importantly, an OLED containing this exciplex system as an emitting layer showed deep-blue emission with Commission Internationale de l’Eclairage coordinates of (0.16, 0.12), a peak luminance of 15,148 cd m−2, and a rather high maximum external quantum efficiency of 10.2% along with a low roll-off. This study not only reports an efficient exciplex-based deep-blue emitter but also presents a feasible pathway to construct highly efficient deep-blue OLEDs based on exciplex systems.

2021 ◽  
Author(s):  
XinYe Wang ◽  
Yuan Wu ◽  
ChuanMing Wu ◽  
Yixiang Li ◽  
Dongdong Wang ◽  
...  

Two novel molecular scaffolds, dibenzo[f,h]furo[2,3-b]quinoxaline (diBFQ) and its derivative, 3,6-bis(4-isopropylphenyls)-11-phenyldibenzo[f,h]furo[2,3-b]quinoxaline (dP-diBFQ), and furo[2',3':5,6]pyrazino[2,3-f][1,10]phenanthroline (FPPhen), were designed and syn-thesized for highly efficient pure and deep blue emission. The unsubstituted molecule scaffold...


2011 ◽  
Vol 11 (2) ◽  
pp. 1381-1384
Author(s):  
Young Wook Park ◽  
Young Min Kim ◽  
Jin Hwan Choi ◽  
Tae Hyun Park ◽  
Hyun Ju Choi ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (88) ◽  
pp. 72009-72018 ◽  
Author(s):  
Shuo Chen ◽  
Yukun Wu ◽  
Yi Zhao ◽  
Daining Fang

Novel phenanthroimidazole derivatives with D–π–A structures have been successfully designed and prepared. Non-doped organic light emitting diodes (OLEDs) were fabricated by employing the compounds, which display deep blue emission.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2867
Author(s):  
Jixin Jiang ◽  
Weiye Zheng ◽  
Junfei Chen ◽  
Zheng Xu ◽  
Dandan Song ◽  
...  

Nowadays, most blue organic light emitting diodes (OLEDs) are fabricated by using sky-blue emitters which are more easily synthesized when compared with other deep blue emitters. Herein, we put forward a new idea of using an optical micro-cavity based on metal electrodes to regulate electroluminance (EL) spectra of sky-blue organic light emitting diodes to obtain a saturated deep blue emission with a narrowed full-width at half-maximum (FWHM). First, we simulate micro-cavity OLEDs and find that the transmission of the anode plays an important role in the forward emission. Meanwhile, the optical path of micro-cavity OLEDs as well as the phase shifting from electrodes influence the EL spectra and induce the extra intensity enhancement. The results show that when the resonant cavity optical path is regulated by changing the thickness of emitting layer (EML) from 25 nm to 75 nm in the micro-cavity, the EL peak of blue OLEDs has a redshift from 479 nm to 493 nm with FWHM shifting from 69.8 nm to 83.2 nm, when compared to the device without the micro-cavity, whose approximate EL peak and FWHM are 487 nm and 87 nm, respectively. However, the efficiency of electroluminescence decreases in micro-cavity OLEDs. We speculate that this is on account of the ohmic contact between ITO and Ag, the surface plasma effect and the rough morphology induced by Ag electrodes.


2020 ◽  
Vol 8 (30) ◽  
pp. 10185-10190
Author(s):  
Jianhui Xin ◽  
Zhiqiang Li ◽  
Yijun Liu ◽  
Dan Liu ◽  
Feng Zhu ◽  
...  

The non-doped OLEDs with 2FPPICz and 2FPPIPCz as emitters exhibit deep-blue emission with maximum external quantum efficiencies of 4.3% and 5.6%, respectively. The device with 2FPPIPCz has a high emission luminance up to 24 150 cd m−2 and a low efficiency roll-off at 1000 cd m−2.


2020 ◽  
Vol 20 (11) ◽  
pp. 6648-6652
Author(s):  
Jinho Park ◽  
Beomsu Jang ◽  
Yu Ji Moon ◽  
Hakjun Lee ◽  
Young Kwan Kim ◽  
...  

In this study, we synthesized and characterized two novel deep blue emitting materials based on indenoquinoline-substituted phenylanthracene derivatives. Multilayer organic light-emitting diodes were fabricated with the following sequence: indium-tin-oxide (ITO)/4,4′,4″-tris[2-naphthyl(phenyl)amino (2-TNATA)/4,4′-bis(N-N-naphthyl)-N-phenylamino) biphenyl (NPB)/Blue emitting material (1 or 2)/Bathophenanthroline (Bphen)/lithium quinolate (Liq)/Al. A device B using ‘7,7-dimethyl-9-(10-phenylanthracen-9-yl)-7H-indeno[1,2-f] isoquinoline (2)’ as an emitter showed the efficient emission with the luminous efficiency, power efficiency, and external quantum efficiency of 2.30 cd/A, 1.02 lm/W, 2.94% at 20 mA/cm2, respectively. This device exhibited deep-blue emission with the Commission Internationale De LÉnclairage (CIE) coordinates of (0.16, 0.08) and λmax = 436 nm at 8.0 V.


2016 ◽  
Vol 4 (39) ◽  
pp. 9310-9315 ◽  
Author(s):  
Samik Jhulki ◽  
Abhaya Kumar Mishra ◽  
Avijit Ghosh ◽  
Tahsin J. Chow ◽  
Jarugu Narasimha Moorthy

Phenanthrenes functionalized two-fold at 3,6 positions by fluorophoric amines, i.e., PTPA, PDPA and PCZL, serve as very good bifunctional materials (HTM + EM) with deep blue emission in simple double layer OLED devices.


2018 ◽  
Vol 6 (15) ◽  
pp. 3845-3848 ◽  
Author(s):  
Lorenz Graf von Reventlow ◽  
Matthias Bremer ◽  
Bernd Ebenhoch ◽  
Martina Gerken ◽  
Timothy W. Schmidt ◽  
...  

Deep-blue emission from a green OLED is obtained by adding a thin gelled upconversion layer and additional dichroic filters.


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