Suppressing singlet–triplet annihilation processes to achieve highly efficient deep-blue AIE-based OLEDs

Lin, Chengwei; Han, Pengbo; Qu, Fenlan; Shu, Xiao Ou; Li, Yuanzhao; Xie, Dian; Qiao, Xianfeng; Yang, Dezhi; Dai, Yanfeng; Sun, Qian; Qin, Anjun; Tang, Ben Zhong; Ma, Dongge

doi:10.1039/d2mh00627h

Cited by 32 publications

(23 citation statements)

References 40 publications

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“…The corresponding absolute PLQY values were 34%, 36%, and 37%, respectively, for TDBA-BCZ and 48%, 58%, and 52%, respectively, for TDBA-PCZ. Interestingly, both emitters exhibited higher PLQY values in the neat-film state than in the solution state, suggesting an aggregation-induced emission (AIE) effect [ 41 , 42 , 43 , 44 ]. In order to investigate the AIE effect of the two emitters, we measured the PLQY values of TDBA-BCZ and TDBA-PCZ in THF/water mixtures with different water fractions (fws) ( Figure S5 ).…”

Section: Resultsmentioning

confidence: 99%

Organic–Inorganic Hybrid Device with a Novel Deep-Blue Emitter of a Donor–Acceptor Type, with ZnO Nanoparticles for Solution-Processed OLEDs

et al. 2022

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Two new deep-blue emitters with bipolar properties based on an organoboron acceptor and carbazole donor were newly synthesized: 2-(9H-carbazol-9-yl)-5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-5H-benzo[b]carbazole (TDBA-BCZ) and 5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-8-phenyl-5,8-dihydroindolo[2,3-c]carbazole (TDBA-PCZ). The two emitters showed deep-blue and real-blue photoluminescence emission in their solution and film states, respectively. The doped spin-coated films were prepared using synthesized materials and showed a root-mean-square roughness of less than 0.52 nm, indicating excellent surface morphology. The doped devices, fabricated via a solution process using TDBA-BCZ and TDBA-PCZ as the dopants, showed electroluminescence peaks at 428 and 461 nm, corresponding to the Commission Internationale de L’éclairage (CIE) coordinates of (0.161, 0.046) and (0.151, 0.155), respectively. The external quantum efficiency (EQE)/current efficiency (CE) of the solution-processed forward devices, with TDBA-BCZ and TDBA-PCZ as dopants, were 7.73%/8.67 cd/A and 10.58%/14.24 cd/A, respectively. An inverted OLED device fabricated using rod-shaped ZnO nanoparticles as an electron injection layer showed a CE of 1.09 cd/A and an EQE of 0.30%.

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Section: Resultsmentioning

confidence: 99%

Organic–Inorganic Hybrid Device with a Novel Deep-Blue Emitter of a Donor–Acceptor Type, with ZnO Nanoparticles for Solution-Processed OLEDs

et al. 2022

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“…OLEDs have been regarded as the next-generation display, wearable devices, and lighting, owing to their flexibility, low cost, fast response, and low power driving. [71][72][73] However, in order to relieve the ACQ effect of emitting layers, the majority of OLEDs were fabricated via host-guest doping system, but they still possess several drawbacks that remain to be solved, such as, i) high cost of introducing hosts, ii) imprecise control dopant codeposition, and iii) difficulty of obtaining universal hosts. [74] Given the circumstances, utilization of AIEgens to construct OLEDs became an ideal candidate.…”

Section: Luminescence Propertiesmentioning

confidence: 99%

As Fiber Meets with AIE: Opening a Wonderland for Smart Flexible Materials

Jin

Wang

et al. 2022

Advanced Materials

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Aggregation‐induced emission luminogens (AIEgens) have recently been developed at a tremendous pace in the area of organic luminescent materials by virtue of their superior properties. However, the practical applications of AIEgens still face the challenge of transforming AIEgens from molecules into materials. Till now, many AIEgens have been integrated into fiber, endowing the fiber with prominent fluorescence and/or photosensitizing capacities. AIEgens and fiber complement each other for making progress in flexible smart materials, in which the utilization of AIEgens creates new application possibilities for fiber, and the fiber provides an excellent carrier for AIEgens towards realizing the conversion from molecule to materials and an ideal platform to research the aggregate state of AIEgens in mesoscale and macroscale. This review begins with a brief summary of the recent advances related to some typical AIEgens with various functions and the technology for the fabrication of AIEgen‐functionalized fiber. The most representative applications are then highlighted by focusing on energy conversion, personal protective equipment, biomedical, sensor, and fluorescence‐related fields. Finally, the challenges, opportunities, and tendencies in future development are discussed in detail. This review hopes to inspire innovation in AIEgens and fiber from the view of mesoscale and macroscale.

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“…Recently, aggregation-induced emission (AIE) materials with the hRISC process and an extremely high PLQY in the film have been considered as a promising alternative to achieve high-efficiency fluorescence OLEDs with a small efficiency roll-off. [18,19,21] In this work, we conducted in-depth research on the EL processes in an AIE material 2″,5″-bis(4-(diphenylamine)phenyl)-[1,1″:4″″,1″-terphenyl]-4,4″″-dicarbonitrile (iTPB-2AC) with hRISC process, and found that the triplet exciton losses caused IC process greatly reduced the efficiency of the resulting blue OLEDs based on iTPB-2AC as the emitter. In order to better reuse the lost triplet excitons and further improve device efficiency, we strategically designed a device structure that can efficiently manage the triplet excitons on T 1 of iTPB-2AC by introducing two TTA up-conversion channels using DMPPP and CzPA.…”

Section: Introductionmentioning

confidence: 99%

Strategic Management of High‐Lying Triplet Excitons to Realize the Breakthrough in Efficiency of Blue Fluorescence OLEDs Based on AIE Emitter

Lin

Han

et al. 2023

Advanced Optical Materials

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Aggregation‐induced emission (AIE) materials are attractive for the fabrication of high‐efficiency organic light‐emitting diodes (OLEDs) owing to the “hot exciton” process by reverse intersystem crossing (hRISC) and high photoluminescence quantum yields (PLQY). However, the internal conversion (IC) from the high‐lying triplet excitation states (Tn, n≥2) to the lower excited triplet state (Tn‐1) is inevitable, resulting in severe exciton losses. Herein, an effective device structure is designed that reuses the lost triplet excitons caused by IC and realizes the breakthrough in the efficiency of blue fluorescence OLEDs based on AIE molecule as an emitter. The maximum external quantum efficiency reached as high as 14.8% and is kept at 14.4% at the luminance of 1000 cd m−2. In the designed device, a triplet–triplet annihilation (TTA) up‐conversion material 1‐[2,5‐dimethyl‐4‐(1‐pyrenyl)phenyl]pyrene (DMPPP) is introduced into the AIE emitter as a triplet sensitizer to receive the lost triplet excitons, and a thin TTA up‐conversion layer 9‐[4‐(10‐phenyl‐9‐anthryl)phenyl]‐9H‐carbazole (CzPA) is introduced in the middle of the doped layer to form the emissive layer (EML). It is found that the hRISC process of iTPB‐2AC greatly enhances the utilization efficiency of TTA intermediate state ([TT]*) excitons on CzPA to iTPB‐2AC so that the utilization of the lost excitons is maximized. This work establishes physical insights into the AIE emission materials and device fabrication of high‐efficiency blue fluorescence OLEDs.

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Suppressing singlet–triplet annihilation processes to achieve highly efficient deep-blue AIE-based OLEDs

Abstract: Aggregation-induced emission (AIE) materials are attractive for the fabrication of high efficiency organic light-emitting diodes (OLEDs) by harnessing “hot excitons” from high-lying triplet exciton states (Tn, n>2) and high photoluminescence...

Cited by 32 publications

References 40 publications

Organic–Inorganic Hybrid Device with a Novel Deep-Blue Emitter of a Donor–Acceptor Type, with ZnO Nanoparticles for Solution-Processed OLEDs

Organic–Inorganic Hybrid Device with a Novel Deep-Blue Emitter of a Donor–Acceptor Type, with ZnO Nanoparticles for Solution-Processed OLEDs

As Fiber Meets with AIE: Opening a Wonderland for Smart Flexible Materials

Strategic Management of High‐Lying Triplet Excitons to Realize the Breakthrough in Efficiency of Blue Fluorescence OLEDs Based on AIE Emitter

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