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
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Xiaoman Bi,Weiwei Zuo,Yingliang Liu,Zhenru Zhang,Cen Zeng,Shengang Xu,Shaokui Cao
Organic light-emitting molecular glasses (OEMGs) are synthesized through the introduction of nonplanar donor and branched aliphatic chain into electroluminescent emitters. The target OEMGs are characterized by 1 H NMR, 13 C NMR, IR, UV–vis and fluorescent spectra as well as elemental analysis, TG and DSC. The results indicated that the optical, electrochemical and electroluminescent properties of OEMGs are adjusted successfully by the replacement of electron-donating group. The non-doped OLED device with a standard red electroluminescent emission is achieved by spin-coating the THF solution of OEMG with a triphenylamine moiety. This non-doped red OLED device takes on an electrically stable electroluminescent performance, including the stable maximum electroluminescent wavelength of 640 nm, the stable luminous efficiency of 2.4 cd/A and the stable CIE1931 coordinate of ( x , y ) = (0.64, 0.35), which is basically in accord with the CIE1931 coordinate ( x , y ) = (0.64, 0.33) of standard red light in PAL system.
研究领域:
材料科学
·
光学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 29
·12945-12956
·
IF 3.591
Zhenghui Yang,Haiquan Guo,Chuanqing Kang,Lianxun Gao
A series of polymer substrates based on the polyimides (PIs) containing diphenylpyridine for flexible OLED displays were successfully fabricated by the incorporation of graphene oxide (GO) and organically modified layered double hydroxide (OLDH) nanosheets. In comparison with pristine PI, the OTR and WVTR of PI nanocomposite films at a loading of 3% OLDH were reduced by 78% and 25.7%, respectively, whereas by incorporation of 0.3% GO, the OTR and WVTR of PI nanocomposite films declined by 85.5% and 31.8%, respectively. The results revealed that GO nanosheets could have a great advantage over OLDH from the aspect of improving the gas barrier performance. Moreover, compared with the pristine PI films (CTE: 4.73 ppm K−1), the incorporation of GO and OLDH nanosheets was of great benefit in reducing the CTE value, such as 1.57 ppm K−1 for PIL-3.0 and 3.33 ppm K−1 for PIG-0.3, while maintaining high Tg values exceeding 450 °C and excellent thermal stability. The resulting PI nanocomposite films showed improved barrier properties without sacrificing the thermal and mechanical performance, and could serve as a promising candidate for substrate materials of flexible OLED displays.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2016
·
IF 4.055
Yafei Wang,Jiang Fan,Junwei Shi,Hongrui Qi,Etienne Baranoff,Guohua Xie,Qingguo Li,Hua Tan,Yu Liu,Weiguo Zhu
In this context, a series of platinum complexes containing a triphenylene unit, namely Pt5 Pt8 , was prepared and characterized. Platinum complex Pt6 shows a clearly column liquid crystalline property, confirmed by differential scanning calorimetry , polarized optical microscopy and X-ray diffraction. These platinum complexes only display monomolecular emission both in solution and in neat film, an effect attributed to the presence of carbazole as a bulky group disfavoring aggregation of the complexes. Hole mobilities in the range of 10 −5 –10 −6 cm 2 V −1 s −1 were obtained for the annealed platinum complexes films. It was found that the method to align the emissive layer has a crucial role on the performance of the devices. The first example of polarized phosphorescent white organic light-emitting diode (OLED) with polarized ratio of 1.4 was achieved in Pt6 -based device. This research opens up a new aspect of phosphorescent metallomesogens application for polarized white light emission.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2021
·
IF 4.837
Tao Wang,Li-Chao Jing,Zelong Bao,Pengfei Qian,Wenming Geng,Anita Sagadevan Ethiraj,Wen-Hao Geng,Lvyun Chen,Qingxia Zhu,Hong-Zhang Geng
Carbon nanotubes (CNTs) and graphene (Gr) are promising materials for flexible transparent conductive films (TCFs) in optoelectronic application because of their exceptional electrical, optical, and mechanical properties . Here, high-quality graphene nanosheets were synthesized by the one-step green method which using natural polyphenols-gallic acid (GA) as the exfoliation medium through high-pressure homogenization ; besides, GA molecules can also be used as a non-covalent modifier to obtain GA modified CNTs (GCNTs). Then, the Au decorated Gr/GCNT-PET (Au-Gr/GCNT-PET) TCFs were obtained by a simple spray-coating process. The TCFs exhibited an excellent optoelectronic performance ( Rs = 45.6 Ω/sq., T = ca. 80% at 550 nm), relatively flat surface (roughness = 12.43 nm), good bending resistance (the ΔR Au-Gr/GCNT-PET TCF /R 0 was 0.07 after 1000 times bending tests) and strong adhesion (the f T of all Au-Gr/GCNT PET films was higher than 0.8). Finally, the Au-Gr/GCNT-PET films were used as an anode to prepare flexible green-light OLED devices; the maximum luminance of the Au-Gr/GCNT-PET device was 6554.1 cd/m 2 at 15V, and the maximum current efficiency was 4.03 cd/A. It confirmed that this type of TCFs has considerable potential application in photovoltaic devices .
研究领域:
材料科学
·
光电应用
✓ 已验证
产品关联
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
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Xueshuang Jiang,Kaijin Chen,Chuying Li,Yubo Long,Siwei Liu,Zhenguo Chi,Jiarui Xu,Yi Zhang
Colorless polyimides (CPIs) are a key substrate material for flexible organic light-emitting diode (OLED) displays and have attracted worldwide attention. Here, in this paper, the dispersion and interfacial interaction of aromatic polyamide (PA) in CPI (synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,2′-bis(trifluoromethyl)benzidine (TFMB)) were significantly improved by in situ polymerization, and colorless transparent macromolecular polyimide composites (CPI-PAx) were successfully prepared by PA and CPI. By adjusting the ratio of PA to CPI, a high-performance engineering plastic with excellent film-forming properties was obtained. Molecular simulations confirmed the uniform distribution of PA in CPI and its interaction in polymers. In CPI-PAx, the CPI was locked by the PA chain, and numerous molecular chains were mutually entangled to form a hydrogen-bond network structure. Due to the strong interaction between the chains imparted by the hydrogen bonds of the PA, they do not slide under external forces and heating. In addition, the additive PA has excellent dimensional stability, thermal, and mechanical properties, and CPI has outstanding optical properties, so the synthesized CPI-PAx combines the comprehensive properties of PA and CPI. The CPI-PAx has excellent thermal and mechanical properties, with a thermal decomposition temperature of 499 °C, a glass transition temperature of 385 °C, a coefficient of thermal expansion of 0.8 ppm K–1, a tensile strength of 50.9 MPa, and an elastic modulus of 3.9 GPa. Particularly, CPI-PAx has a 90% transmittance in the visible region. These data prove that the strategy of combining PA and CPI by in situ polymerization is an effective method to circumvent the bottleneck of CPI in the current flexible window application, and this design strategy is universal.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2024
·
IF 4.1
Zhiming Zhong,Tingxin Chen,Feng Peng,Pengfei Niu,Jin Xu,Lei Ying
Blue organic light-emitting diodes with non-doped emissive layer (EML) structures have been garnered increasing interest due to their convenience of manufacturing process. For this purpose, we designed and synthesized two novel anthracene derivatives, PO2PhAnTz and PO2PhAnBI. Both derivatives exhibited bright blue electroluminescence emission and a relatively low operating voltage with a simple bilayer device structure. The PO2PhAnBI with triphenyl-phosphine oxide moiety as host, anthracene core as dopant and benzimidazole as electron transport group, realized a balanced bipolar transport and attained a maximum external quantum efficiency of 5.74 %. The findings shed light on the molecule design role toward high-efficiency non-doped blue OLEDs.
研究领域:
材料科学
·
有机电子学
✓ 已验证
DOI
高影响因子
TETRAHEDRON
·
2022
·
IF 2.388
Yanan Gao,Xinwen Zhang,Jie Song,Liwei Dou,Hong Gao,Shibin Shang,Zhanqian Song
Dehydroabietic acid triarylamine (DTPA) synthesized from renewable natural rosin is an excellent hole-transporting material but is affected by aggregation-caused quenching in the solid state. Herein, two new biomass-based AIE luminogens (AIEgens), namely DTPA-TPE and 2DTPA-TPE, were synthesized through the attachment of DTPA to tetraphenylethene (TPE). Their aggregates in poor solvents and thin films have a strong emission with a fluorescence quantum yield of up to 67.4%. DTPA AIEgens exhibit superior thermal and morphological stability, showing high thermal degradation ( T 5d up to 412.0 °C) and glass transition ( T g up to 150.8 °C) temperatures. Electroluminescence (EL) devices with compounds used either as emitting layers (EMLs) or as EMLs and hole-transporting layers (HTLs) were constructed. The device with 2DTPA-TPE as the EML exhibits the best performance (turn-on voltage of 2.4 V, maximum luminance of 12,414 cd m −2 , current efficiency of 6.2 cd A −1 , and power efficiency of 6.5 lm W −1 ). The devices without the HTL ( N , N ′-di-1-naphthyl- N , N ′-diphenylbenzidine (NPB)) exhibit performances comparable with or better than those of the devices with NPB. These results indicate that these compounds are promising luminescent materials for non-doped organic light-emitting diodes.
研究领域:
有机化学
·
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2020
·
IF 3.31
Mengdi Wang,Wenqing Zhu,Zhengyuan Yin,Lu Huang,Jun Li
The hole-injection layer (HIL) has vital impacts on the electroluminescence performance of organic light-emitting diodes (OLEDs). Herein, low-temperature solution-processed Li-doped nickel oxide (Li:NiO x ) was fabricated as a novel HIL for OLEDs. As a result, the phosphorescent green OLED with 5% molar ratio Li:NiO x exhibits the best performance with low turn-on voltage of 3.1 V, maximum current efficiency of 55.8 cd A −1 , maximum power efficiency of 57.2 lm·W −1 and maximum external quantum efficiency of 17.1%. While it is only 52.1 cd A −1 , 50.9 lm·W −1 and for the reference device with undoped NiO x film, corresponding a 7%, 12% and 8% enhancement in efficiency respectively . It reveals that the improved efficiency of the Li:NiO x film HIL based device with is mainly ascribed to the synergistic effect of extrinsic doping in the aspects of achieving enhanced hole injection. Our work demonstrates that the solution-processed Li-doped NiO x film is a promising HIL for high-performance OLEDs.
研究领域:
材料科学
·
光电材料
·
显示技术
✓ 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
危险品化学品经营许可证（带存储）