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Chunya Du Hui Liu Zhuang Cheng Shaoqin Zhang Zexing Qu Dezhi Yang Xianfeng Qiao Zujin Zhao Ping Lu 《Advanced functional materials》2023,33(45):2304854
The pursuit for efficient deep blue material is an ever-increasing issue in organic optoelectronics field. It is a long-standing challenge to achieve high external quantum efficiency (EQE) exceed 10% at brightness of 1000 cd m−2 with a Commission International de L'Eclairage (CIEy) <0.08 in non-doped organic light-emitting diodes (OLEDs). Herein, this study reports a deep blue luminogen, PPITPh, by bonding phenanthro[9,10-d]imidazole moiety with m-terphenyl group via benzene bridge. The non-doped OLED based on PPITPh exhibits an exceptionally high EQE of 11.83% with a CIE coordinate of (0.15, 0.07). The EQE still maintains 10.17% at the brightness of 1000 cd m−2, and even at a brightness as high as 10000 cd m−2, an EQE of 7.5% is still remained, representing the record-high result among non-doped deep-blue OLEDs at 1000 cd m−2. The unprecedented device performance is attributed to the reversed intersystem crossing process through hot exciton mechanism. Besides, the maximum EQE of orange phosphorescent OLED with PPITPh as host is 32.02%, and remains 31.17% at the brightness of 1000 cd m−2. Such minimal efficiency roll-off demonstrates that PPITPh is also an excellent phosphorescent host material. The result offers a new design strategy for the enrichment of high-efficiency deep blue luminogen. 相似文献
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Hao Li Mengna Yu Jiabin Gu Qiujing Bao Yangcheng Wang Yang Li Yan Ma Lubing Bai Zhiqiang Zhuo Yunlong Zhang Jingrui Zhang Yeyang Wang Manman Luo Yiren Liu Chenghui Li Jinyi Lin Xinwen Zhang Quanyou Feng Linghai Xie 《Advanced functional materials》2023,33(40):2303947
In the field of flexible light-emitting display, goal-oriented intelligent molecular design is used to control various behaviors of molecules, which provides potential for the development of flexible light-emitting conjugated polymers (LCPs). The introduction of non-conjugated units into polymer molecules is a key prerequisite for realizing the intrinsic flexibility, but its easy interchain slip will also lead to the formation of interchain excited states, which is detrimental to the efficiency of light-emitting diodes. Herein, two kinds of fluorene-based rod-coil copolymer with stable deep blue emission characteristics is presented and with Commission Internationale de L'Eclairage (CIE) coordinates of (0.18, 0.14) and (0.15, 0.09), respectively. Surprisingly, the copolymer films show efficient blue emission even at 100% tension. Meanwhile, the rod-coil copolymer possesses better aging resistance compared to rigid π-conjugated counterparts. Finally, both rigid and flexible light-emitting diodes based on rod-coil copolymer exhibit stable deep blue emission, and the G2-based PLED with CIE coordinates of (0.16, 0.08), which approach National Television System Committee standard blue specification. These results confirm the validity of rod-coil copolymer design strategy in constructing inherently flexible polymers with deep blue emission, which have great application potential in flexible PLEDs. 相似文献
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HONG-JUN YOU QIONG DU ZHI-YONG ZHANG CHUAN-JIANG LI JINGTAO GUAN BEN-MEI WEI 《Polycyclic Aromatic Compounds》2013,33(5):589-599
A series of novel blue light-emitting materials, spirofluorene derivatives, DBSF, 3DBSF, and 5DBSF, based on 2′,7′-dibromospiro- [benzo[c]fluorene-7,9′-fluorene] (DBrSPFF) were successfully synthesized and identified by IR, 1H-NMR, and13C-NMR, MS. Optical properties were examined by UV-Vis absorption spectra and photoluminescence (PL) emission spectra. They performed great blue light characteristics. PL quantum yield was calculated by using quinine sulphate in 0.1M H2SO4 as standard. Electro-chemical behavior was examined through cyclic voltammeter measurement. They may be potential promising blue light-emitting materials for OLED. 相似文献
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Dongdong Zhang Xiaozeng Song Alexander J. Gillett Bluebell H. Drummond Saul T. E. Jones Guomeng Li Hanqing He Minghan Cai Dan Credgington Lian Duan 《Advanced materials (Deerfield Beach, Fla.)》2020,32(19):1908355
Multiple donor–acceptor-type carbazole–benzonitrile derivatives that exhibit thermally activated delayed fluorescence (TADF) are the state of the art in efficiency and stability in sky-blue organic light-emitting diodes. However, such a motif still suffers from low reverse intersystem crossing rates (kRISC) with emission peaks <470 nm. Here, a weak acceptor of cyanophenyl is adopted to replace the stronger cyano one to construct blue emitters with multiple donors and acceptors. Both linear donor–π–donor and acceptor–π–acceptor structures are observed to facilitate delocalized excited states for enhanced mixing between charge-transfer and locally excited states. Consequently, a high kRISC of 2.36 × 106 s−1 with an emission peak of 456 nm and a maximum external quantum efficiency of 22.8% is achieved. When utilizing this material to sensitize a blue multiple-resonance TADF emitter, the corresponding device simultaneously realizes a maximum external quantum efficiency of 32.5%, CIEy ≈ 0.12, a full width at half maximum of 29 nm, and a T80 (time to 80% of the initial luminance) of > 60 h at an initial luminance of 1000 cd m−2. 相似文献
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Tanguy Leyder Julien Mignon Denis Mottet Catherine Michaux 《International journal of molecular sciences》2022,23(23)
Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu2+, Mg2+, Ni2+, and Zn2+, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu2+ and Ni2+ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg2+ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn2+ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg2+ and Zn2+ cations. 相似文献
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Hyoungcheol Lim Hyung Jin Cheon Seung-Je Woo Soon-Ki Kwon Yun-Hi Kim Jang-Joo Kim 《Advanced materials (Deerfield Beach, Fla.)》2020,32(47):2004083
New blue (DBA-SAB) and deep-blue (TDBA-SAF) thermally activated delayed fluorescence (TADF) emitters are synthesized for blue-emitting organic-light emitting diodes (OLEDs) by incorporating spiro-biacridine and spiro-acridine fluorene donor units with an oxygen-bridged boron acceptor unit, respectively. The molecules show blue and deep-blue emission because of the deep highest occupied molecular energy levels of the donor units. Besides, both emitters exhibit narrow emission spectra with the full-width at half maximum (FWHM) of less than 65 nm due to the rigid donor and acceptor units. In addition, the long molecular structure along the transition dipole moment direction results in a high horizontal emitting dipole ratio over 80%. By combining the effects, the OLED utilizing DBA-SAB as the emitter exhibits a maximum external quantum efficiency (EQE) of 25.7% and 1931 Commission Internationale de l'éclairage (CIE) coordinates of (0.144, 0.212). Even a higher efficiency deep blue TADF OLED with a maximum EQE of 28.2% and CIE coordinates of (0.142, 0.090) is realized using TDBA-SAF as the emitter. 相似文献
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Yang Shen Kong-Chao Shen Yan-Qing Li Minglei Guo Jingkun Wang Yongchun Ye Feng-Ming Xie Hao Ren Xingyu Gao Fei Song Jian-Xin Tang 《Advanced functional materials》2021,31(6):2006736
Perovskite light-emitting diodes (PeLEDs) are emerging candidates for the applications of solution-processed full-color displays. However, the device performance of deep-blue PeLED still lags far behind that of their red and green counterparts, which is largely limited by low external quantum efficiency (EQE) and poor operational stability. Here, a facile and reliable crystallization strategy for perovskite grains is proposed, with improved deep-blue emission through rational interfacial engineering. By modifying the substrate with potassium cation (K+) as the supplier of heterogeneous nucleation seeds, the interfacial K+-guided grain growth is realized for well-packed perovskite assemblies with high surface coverage and the controlled crystal orientation, leading to the enhanced radiative recombination and hole-transport capabilities. Synergistical boost in device performance is achieved for deep-blue PeLEDs emitting at 469 nm with a peak EQE of 4.14%, a maximum luminance of 451 cd m–2, and spectrally stable color coordinates of (0.125, 0.076) that matches well with the National Television System Committee (NTSC) standard blue. 相似文献
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Guangruixing Zou Zhenchao Li Ziming Chen Linghao Chu Hin-Lap Yip Yong Cao 《Advanced functional materials》2021,31(46):2103219
Recent studies of sky-blue perovskite light-emitting diodes (PeLEDs) have extensively promoted optimal device design to achieve an external quantum efficiency (EQE) above 12%. However, the development of thin-film deep-blue PeLEDs lags dramatically behind, especially with regards to meeting the latest Rec. 2020 standard. A trichloro(3,3,3-trifluoropropyl) silane post-treatment that drives the emission of perovskite into the deep-blue region, ranging from 440 to 460 nm, which meets the Rec. 2020 standard, is proposed. The chlorine ions released from the organotrichlorosilane molecules during their polycondensation reaction provide an addition halide source to fine tune the composition of the mixed halide perovskite films, leading to increase of bandgap and deep-blue emission. In addition, hydrogen bonds between the hydroxy groups of silane molecules and halide anions in perovskite can suppress ion migration for improving emission stability. As a result, an optimal PeLED is developed with deep-blue emission at 458 nm and excellent color stability, which yields an EQE and luminance of 1.1% and 130 cd m−2, respectively, representing a state-of-the-art result for thin-film PeLEDs in this emission region. This work paves the way to achieve high-performance deep-blue PeLEDs with stable emissions to meet the demand for potential applications such as full-color display. 相似文献
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Hao Zhang Jianan Xue Chenglong Li Shitong Zhang Bing Yang Yu Liu Yue Wang 《Advanced functional materials》2021,31(25):2100704
A new hybrid local and charge transfer (HLCT) molecule 2TPA-PPI is obtained for constructing the high-performance organic light-emitting diodes (OLEDs) in this work. 2TPA-PPI possesses the sufficient emission/charge-transporting properties, thus it is used as a neat emitter achieving an efficient deep-blue OLED with very high external quantum efficiency (EQE) up to 10.7%, as well as a multi-functional emitting host matrix constructing the high-performance phosphorescent OLEDs. More importantly, a high-efficiency candle light-style OLED adopting the HLCT/phosphor hybrid strategy is realized, where 2TPA-PPI acts as not only a blue emitter, but also a universal host sensitizing both yellow and red phosphors. This quasi-white OLED represents almost the highest EQE/PE level of 25.2%/49.7 lm W−1 at the practical luminance level of 1000 cd m−2 for the white OLEDs with the excellent color rendering index values of more than 80 reported. 相似文献
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Ho-Yeol Park Athithan Maheshwaran Chang-Ki Moon Hyuna Lee Saripally Sudhaker Reddy Vijaya Gopalan Sree Jiyoung Yoon Jeong Won Kim Jang Hyuk Kwon Jang-Joo Kim Sung-Ho Jin 《Advanced materials (Deerfield Beach, Fla.)》2020,32(29):2002120
Deep-blue triplet emitters remain far inferior to standard red and green triplet emitters in terms of exhibiting high-color-purity Commission International de l'Éclairage (CIE) y values of ≤0.1, external quantum efficiencies (EQEs), and high electroluminescent brightnesses in phosphorescent organic light-emitting diodes. In fact, no deep-blue triplet emitter with color purity and high device performance has previously been reported. In this study, a deep-blue triplet emitter, mer-tris(N-phenyl, N-benzyl-pyridoimidazol-2-yl)iridium(III) (mer-Ir1) is developed, which meets the requirements of the National Television System Committee (NTSC) CIE(x, y) coordinates of (0.149, 0.085) with an extremely high EQE of 24.8% and maximum brightness (Lmax) of 6453 cd m−2, by a device with a 40 vol% doping ratio. Moreover, another device demonstrates an EQEmax of 21.3%, an Lmax of 5247 cd m−2, and CIE(x, y) coordinates of (0.151, 0.086) at a 30 vol% doping ratio. This is the first report of a high-performance, deep-blue phosphor, carbene-based Ir(III) complex device with outstanding CIE(x, y) color coordinates and a high EQE. The results of this study indicate that the novel dopant mer-Ir1 is a promising candidate for reducing power consumption in display applications. 相似文献
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