OPTICAL MATERIALS
·
2022
·
IF 3.754
Wentong Gao,Wenlu Wu,Shihai Cao,Bing Han,Nengquan Li
Solution-processable host materials play an important role in achieving highly efficient and cost-effective phosphorescent organic light-emitting diodes (PhOLEDs). This paper designed and prepared a simple solution-processable host material of TPA-PyF 2 based on triphenylamine and pyridine to fabricate efficient solution-processed PhOLEDs. TPA-PyF 2 featured an σ-linkage between the electron donor and acceptor units, which not only served to limit the conjugation length of the molecule and maintain a high triplet energy level, but also endowed the host molecule with a three-dimensional structure to enable high film morphological stability for solution processing. As a result, TPA-PyF 2 exhibited a high triplet energy level (2.82 eV), high thermal stability, bipolar charge transfer, and excellent film morphology. Blue solution-processed OLED with a simple double-layer structure based on TPA-PyF 2 host achieved a maximum current efficiency, power efficiency, and luminance of 17.2 cd/A, 7.1 lm/W, and 11519 cd/m 2 , respectively, with a small efficiency roll-off of only 9.1% at the practical luminance of 1000 cd/m 2 . This work reveals that the σ-linkage strategy is promising in designing efficient solution-processable host materials for high-efficiency PhOLEDs.
研究领域:
材料科学
·
有机电子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 26
·期 9
·6563-6571
·
IF 1.569
Lu Tianxing,You Jing,Zhao Dan,Wang Hua,Miao Yanqin,Liu Xicheng,Xiao Yin,Li Xianggao,Wang Shirong
Three s -triazine/carbazole based bipolar molecules: 9,9′,9″-(1,3,5-triazine-2,4,6-triyl)tris(3,6-di- tert -butyl-carbazole) (TazTCz), 9,9′-(6-phenyl-1,3,5-triazine-2,4-diyl)bis(3,6-di- tert -butyl-carbazole) (PhTazDCz) and 9-(4,6-diphenyl-1,3,5-triazine-2-yl)-3,6-di- tert -butyl-carbazole (DPhTazCz) were synthesized and applied as host materials for blue phosphorescent organic light-emitting diodes (PHOLEDs). The triplet state energy levels are ~2.86 eV for these compounds, ensured their application in blue PHOLEDs. X-ray single crystal structural analysis revealed a non-planar structure of TazTCz, which prevented the intermolecular close-packing in the solid state. X-ray diffraction spectra also confirmed that TazTCz and PhTazDCz could form amorphous films with spin-coating method. The bipolar characteristics of as-synthesized compounds were confirmed by carrier mobility measurement. The device parameters of blue PHOLEDs based on these compounds as host materials exhibit that the balance of electron and hole mobilities is benefit for reducing turn-on voltage and efficiency roll-off at high current density.
研究领域:
材料科学
·
有机电子学
✓ 已验证
产品关联
DOI
高影响因子
THIN SOLID FILMS
·
2023
·
IF 2.1
Liang Zhao,Xiaozhe Cheng,Weizhen Xia,Lingling Yao,Zhitao Dou,Haibin Xue,Hong Lian,Yongquan Qu,Qingchen Dong
In this work, we designed and synthesized two bipolar host materials, DBTPC1 and DBTPC2 through different linkage ways between carbazole, pyridine and dibenzothiophene. The photophysical properties and thermal properties of these hosts were systematically investigated. Their rigid molecular structures result in high glass transition temperatures , contributing to excellent thermal stability of molecules. Employing DBTPC1 and DBTPC2 as hosts, red phosphorescent organic light-emitting devices (PHOLEDs) with Ir(piq) 2 acac as an emitter display maximum external quantum efficiencies (EQEs) of 18.8 and 13.2%, respectively. The experimental results reveal that DBTPC1 shows better performance than commercial host 4,4’-bis(carbazol-9-yl)biphenyl (CBP), thus, would be a promising host material for practical application in red PHOLEDs and for the future exploration in multi-color PHOLEDs.
研究领域:
材料科学
·
光电化学
✓ 已验证
DOI
高影响因子
ORGANIC ELECTRONICS
·
2016
·
IF 3.471
Jie Zhang,Xunjin Zhu,Aiguo Zhong,Wenping Jia,Fengshou Wu,Dan Li,Hongbo Tong,Chenglin Wu,Wenyuan Tang,Ping Zhang,Lei Wang,Deman Han
The condensation of different groups substituted salicylaldehydes with aniline and 2,4,5-trifluoroaniline, afforded five one-armed Schiff base ligands HL 1 , HL 2 , HL 3 , HL 4 and HL 5 . And their platinum(II) complexes Pt(L 1 ) 2 , Pt(L 2 ) 2 , Pt(L 3 ) 2 , Pt(L 4 ) 2 , Pt(L 5 ) 2 and PtL 5 · DMSO were prepared through the metallation of ligands with K 2 PtCl 4 . All ligands and complexes were characterized by 1 H NMR, infrared spectroscopy , mass spectrometry and single crystal X-ray diffraction. And their thermal stability, photophysical properties, and electrochemical behaviors were investigated in detail. Using these complexes as phosphorescent emitting materials, blue to orange light-emitting devices were fabricated with moderate efficiencies. The maximum current efficiency, power efficiency, and brightness for the 3.0 wt % Pt(L 3 ) 2 doped OLED are 1.12 cd A −1 , 0.62 l m W −1 and 1521 cd m −2 , respectively. Given the synthetic simplicity and ease of structural variation, the results here indicate that these platinum(II) Schiff base complexes are good candidates for phosphorescent OLEDs.
研究领域:
材料化学
·
发光材料
·
有机电子学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Jingxiang Wang,Hongli Liu,Sen Wu,Yi Jia,Hang Yu,Xianggao Li,Shirong Wang
Recently, developing insoluble cross-linkable functional layers plays a vital role for solution-processed organic light emitting diodes (OLEDs). Here, two vinyl-based cross-linkable hole transporting materials V-TPAVTPD and V-TPAVCBP are designed and synthesized. Additionally, cationic photoinitiator 4-octyloxydiphenyliodonium hexafluoroantimonate (OPPI) is first introduced to chemically induce vinyl-based photo cross-linking process, aiming at lowering cross-linking temperature and enhancing hole mobility. As a result, cross-linking can occur at expressly low temperature of 120 °C with >95% solvent resistance. Moreover, hole mobility is markedly enhanced with the value higher than 10 −3 cm 2 V −1 s −1 . When applying hole transporting layers (HTLs) to solution-processed green and red phosphorescent OLEDs, devices exhibit excellent properties. Particularly, the maximum current efficiency of 54.0 cd A −1 (green), 9.8 cd A −1 (red) and external quantum efficiency of 15.5% (green), 15.0% (red) are obtained when OPPI doped V-TPAVCBP serves as HTL. This low temperature feasible cross-linking process to prepare HTLs with preferable hole mobility promotes the development of OLEDs.
研究领域:
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Qingchen Dong,Feifei Tai,Hong Lian,Zheng Chen,Mingming Hu,Jinhai Huang,Wai-Yeung Wong
Two bipolar host materials H1 ( N -linked carbazole) and H2 ( C-3 -linked carbazole) via changing the substitution position of triazine and carbazole moieties are reported. Their structural and physical properties were fully characterized. The thermal analysis demonstrated that both H1 and H2 are of high thermal stability. The triplet energy levels of H1 and H2 were determined to be 2.64 and 2.7 eV, respectively. Both green and blue OLEDs with H1 and H2 acting as host materials were fabricated to investigate their performances in PHOLED . The green PHOLED based on H1 exhibits the best performance with the maximum current efficiency, maximum power efficiency and maximum brightness of 51.7 cd/A, 37.8 lm/W and 132800 cd/m 2 , respectively, while the blue PHOLED based on H2 shows the best performance with the maximum current efficiency, maximum power efficiency and maximum brightness of 21.6 cd/A, 17.2 lm/W and 16640 cd/m 2 , respectively. The characteristic measurements of OLED devices reveal that both H1 and H2 are promising host materials for practical application. By comparing the commercial host materials of 4,4’-bis(carbazol-9-yl)biphenyl (CBP) and N,N-dicarbazoyl-3,5-benzene (mCP), the power efficiencies of green and blue PHOLED were boosted by 22.3% and 75.5%, respectively.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2016
·
IF 2.183
Hua Ye,Kaifeng Zhou,Hongyu Wu,Kai Chen,Gaozhan Xie,Jingang Hu,Guobing Yan,Songhua Ma,Shi-Jian Su,Yong Cao
A series of novel molecules with wide bandgap based on electron-withdrawing diphenyl phosphine oxide units and electron-donating carbazolyl moieties through insulated unique linkages of flexible chains terminated by oxygen or sulfur atoms as solution-processable host materials were successfully synthesized for the first time, and their thermal, photophysical, and electrochemical properties were studied thoroughly. These materials possess high triplet energy levels ( E T , 2.76–2.77 eV) due to the introduction of alkyl chain to interrupt the conjugation between electron-donor and electron-acceptor. Such high E T could effectively curb the energy from phosphorescent emitter transfer to the host molecules and thus assuring the emission of devices was all from the blue phosphorescent emitter iridium (III) bis [(4,6-difluorophenyl)-pyridinate- N ,C2′]picolinate (FIrpic). Among them, the solution-processed device based on CBCR6OPO without extra vacuum thermal-deposited hole-blocking layer and electron-transporting layer showed the highest maximum current efficiency (CE max ) of 4.16 cd/A. Moreover, the device presented small efficiency roll-off with current efficiency (CE) of 4.05 cd/A at high brightness up to 100 cd/m 2 . Our work suggests the potential applications of the solution-processable materials with wide bandgap in full-color flat-panel displays and organic lighting.
研究领域:
材料科学
·
有机电子学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2015
·
IF 3.966
Yi Chen,Jingwei Xie,Zixing Wang,Jin Cao,Hongwei Chen,Jinhai Huang,Jianhua Zhang,Jianhua Su
Two novel indole-based, bipolar, host materials were designed and synthesized by introducing the triazine unit to the 5-position of indole moiety with a meta -linking strategy. The two host materials exhibited excellence bipolar transport abilities and the meta-linking analog presented a high T g value (>120 °C). Furthermore, their electrochemical and photo-physical properties were also fully characterized and all the results exhibited that the meta -linking strategy made a significant effect on the physical properties of the two hosts. Moreover, the PHOLED devices using 9-(4-(5-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)- 1H -indol-1-yl) phenyl)- 9H -carbazole and 9-(4-(5-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)- 1H -indol-1-yl)phenyl)- 9H -carbazole as hosts were also fabricated to evaluate the practical utilities of host materials. The devices achieved the maximum external quantum efficiencies of 17.53% for para -linking compound and 14.53% for meta -linking analog, respectively. In particular, para -linking compound based device revealed the maximum external quantum efficiency was twice that of the device using 4,4′-bis( N -carbazolyl)-1,10-biphenyl as the host.
研究领域:
有机电子学
·
材料科学
✓ 已验证
DOI
高影响因子
THIN SOLID FILMS
·
2017
·
IF 1.879
Yi Chen,Bo Wang,Jinhai Huang,Lei Wang,Jianhua Su
Two host materials based on spiro[fluorene-9,8′-indolo[3,2,1- de ]acridine] derivatives were designed and synthesized by introducing the benzofuran/benzothiophene unit to the spiro [fluorene-9,8′-indolo[3,2,1- de ]acridine] unit. The two host materials exhibited high triplet energy level (> 2.65 eV) and the benzofuran-substituted derivative presented suitable glass transition temperature (> 130 °C). Their electrochemical and photo-physical properties were also determined. The green phosphorescent organic light-emitting diodes based on the two host materials obtained electroluminescence performances with external quantum efficiencies of 14.3 ± 0.1% and 11.9 ± 0.1%, respectively.
研究领域:
材料科学
·
有机电子学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2018
·
IF 3.767
Bin Jia,Hong Lian,Tijian Sun,Hongen Guo,Xiaozhe Cheng,Jian Wu,Yi Chen,Qingchen Dong,Jinhai Huang
Two host materials H1 and H2 by introducing dibenzothiophene and dibezofuran moieties into the carbazole and pyridine derivative, respectively, are reported. Their structural and physical properties were fully characterized. The thermal analysis demonstrated that both H1 and H2 are thermally stable. The triplet energy levels of H1 and H2 were determined to be 2.66 and 2.51 eV, respectively. Green phosphorescent OLEDs with H1 and H2 acting as host materials were fabricated to investigate their performances in PHOLEDs . Green PHOLED based on H1 shows the best performance with the maximum power efficiency of 50.4 lm/W and the lowest driving voltage of 2.5 eV. The characteristic measurements of OLED devices reveal that both H1 and H2 are promising host materials for practical application. By comparing with the commercial host material of 4,4′-bis(carbazol-9-yl)biphenyl (CBP), the power efficiency of green PHOLED was enhanced by 31.6%.
研究领域:
材料科学
·
有机电子学
·
光电材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）