Fluorescent pyrene-imidazole material for deep-blue organic light-emitting devices

Usman, Khurram; Islam, Amjad; Shah, Syed Hamad Ullah; Javaid, Kashif; Amin, Al; Mustafa, Zeeshan; Wattoo, Abdul Ghafar; Abbas, Nadeem; Ge, Ziyi

doi:10.1016/j.optmat.2021.111582

Cited by 17 publications

(7 citation statements)

References 32 publications

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“…Various starting precursors can be used in a multicomponent condensation reaction to obtain differently substituted imidazole derivatives with structural diversity easily installed at the N1, C2, and C4/5 ring positions. Typical synthesis routes for imidazole‐containing emitter materials introduce electron donor, or π‐spacer and donor groups at C2 [23–30] . These groups tend to be conjugated with the imidazole, as arenes such as phenylene rings adopt a relatively co‐planar conformation.…”

Section: Introductionmentioning

confidence: 99%

“…Typical synthesis routes for imidazole-containing emitter materials introduce electron donor, or π-spacer and donor groups at C2. [23][24][25][26][27][28][29][30] These groups tend to be conjugated with the imidazole, as arenes such as phenylene rings adopt a relatively co-planar conformation. By contrast, phenylene substituents at C5 or N1 adopt a significantly more twisted conformation.…”

Section: Introductionmentioning

confidence: 99%

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Donor Influence on the Optoelectronic Properties of N‐Substituted Tetraphenylimidazole Derivatives

et al. 2023

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Three new 1,2,4,5-tetraphenylimidazole derivatives, 9,9-dimethyl-10-(4-(2,4,5-triphenyl-1H-imidazol-1-yl)phenyl)-9,10-dihydroacridine (DMAC-TPI), 10-(4-(2,4,5-triphenyl-1H-imidazol-1yl)phenyl)-10H-phenoxazine (PXZ-TPI), and 10-(4-(2,4,5-triphenyl-1H-imidazol-1-yl)phenyl)-10H-phenothiazine (PTZ-TPI), bearing different electron donors at the N1 position of the imidazole were synthesised and characterised. DMAC-TPI and PXZ-TPI showed narrow emission at λ PL of 388 and 418 nm in toluene, and in doped films in Zeonex polymer (1 wt.%) at λ PL 381 and 407 nm, respectively, with a full width at half maximum (FWHM) ranging 0.42-0.44 eV. DMAC-TPI and PXZ-TPI are predicted to show very low oscillator strength for the low-energy transitions, which aligns to the observed low photoluminescence quantum yields. Both molecules showed a singlet-triplet energy gap (ΔE ST of around 1.2 eV) that is much too large to enable reverse intersystem crossing and thermally activated delayed fluorescence. Connecting a donor group to TPI at the N1 position can lead to room temperature phosphorescence (RTP), as the example of PTZ-TPI showed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Donor Influence on the Optoelectronic Properties of N‐Substituted Tetraphenylimidazole Derivatives

et al. 2023

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“…3,[6][7][8][9][10][11][12][13][14][15][16][17][18] However, the class of PPI acceptors is relatively single, significantly limiting the development of such materials. Although some other acceptors, 19 such as pyrene-imidazole 20,21,[22][23][24] and 9,10-diphenylimidazole, [25][26][27] have been developed, there is still a need to develop more effective acceptor planes for expanding this HLCT material system. In addition, the influence of the peripheral groups of acceptors needs to be comprehensively investigated.…”

Section: Introductionmentioning

confidence: 99%

Impact of peripheral groups on pyrimidine acceptor-based HLCT materials for efficient deep blue OLED devices

et al. 2022

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“…Recently, many researchers give their great efforts to focus on designing small organic luminescent materials (unipolar) because of their ordered molecular structure, easy purification process, and flexibility in structural modification. An imidazole moiety is more recommended because of its high thermal stability and sensing ability. , The electron-deficient characteristics of imidazole makes the molecule highly polar, and the availability of a lone pair on imidazole nitrogen helps in sensing and allowing efficient electron transfer in devices. The unipolar TPI derivatives fabricated in a N , N ′-dicarbazolyl-4,4′-biphenyl (CBP) host found OLED performances of 1.4% EQE with (0.23, 0.21) CIE coordinates in the blue region with good chemosensing behavior .…”

Section: Introductionmentioning

confidence: 99%

Multifunctional 4,5-Diphenyl-1H-imidazole-Based Luminogens as Near UV/Deep Blue Emitters/Hosts for Organic Light-Emitting Diodes and Selective Picric Acid Detection

et al. 2022

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A series of luminophores (construction of diphenylimidazole (m-CF 3 PTPI) groups functionalized at the N1-positions of imidazole groups) were purposefully designed and synthesized for optoelectronics and for selective detection of nitroaromatic compounds. The luminophores showed deep blue emission in solution, solid, and thinfilm matrix with acceptable quantum yield and good thermal stability (5% weight loss at 258−296 °C). From electrochemical analysis as well as theoretical calculations, the energy gaps of HOMO−LUMO are found to be in good agreement and all of them showed good triplet energy. The luminophores can be explored as hosts for phosphorescent organic lightemitting diodes (PhOLEDs). Furthermore, the m-CF 3 PTPI derivatives were used as emitters for fluorescent OLEDs and hosts (m-CF 3 PTPI-1 and m-CF 3 PTPI-2) for triplet dopants in PhOLEDs. Near-UV emissions were observed for all the doped devices that exhibited electroluminescence (EL) peaks at ∼380−395 nm with a Commission International deL'Eclairage (CIE y ) coordinate of ∼0.09. Of all the devices, the m-CF 3 PTPI-5 (3 wt %)-based device demonstrated a maximum external quantum efficiency (EQE max ) of 2.8%, power efficiency (PE max ) of 0.9 lm/W, current efficiency (CE max ) of 1.3 cd/A, and brightness of 953 cd/m 2 . Moreover, the device was further optimized using a different host approach. SimCP2 displayed the best performance by achieving a high EQE max of 4.0% that is near the theoretical limit of fluorescent materials. Furthermore, m-CF 3 PTPI-1 and m-CF 3 PTPI-2 possessing triplet energies of 2.67 and 2.63 eV, respectively, were used as hosts for efficient green (Ir(ppy) 3 -2.4 eV) PhOLEDs. The m-CF 3 PTPI-2-based device achieved an EQE max of 4.8%, CE max of 17.5 cd/A, PE max of 13.4 lm/W, and maximum brightness (L max ) of 4695 cd/m 2 , much higher than those of the counterpart m-CF 3 PTPI-1-based OLED. Furthermore, due to structural functionality, the detection of nitroaromatic compounds was carried out for all the luminophores. They showed high sensitivity toward picric acid, and the sensing mechanism was thoroughly analyzed by using NMR and DFT study.

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Fluorescent pyrene-imidazole material for deep-blue organic light-emitting devices

Cited by 17 publications

References 32 publications

Donor Influence on the Optoelectronic Properties of N‐Substituted Tetraphenylimidazole Derivatives

Donor Influence on the Optoelectronic Properties of N‐Substituted Tetraphenylimidazole Derivatives

Impact of peripheral groups on pyrimidine acceptor-based HLCT materials for efficient deep blue OLED devices

Multifunctional 4,5-Diphenyl-1H-imidazole-Based Luminogens as Near UV/Deep Blue Emitters/Hosts for Organic Light-Emitting Diodes and Selective Picric Acid Detection

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