- Bipolar host materials for high-efficiency blue phosphorescent and delayed-fluorescence OLEDs
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A series of small molecular isomers, namely o-CzCN, m-CzCN, and p-CzCN, are developed for use as bipolar hosts in blue phosphorescent and fluorescent organic light-emitting diodes (OLEDs). Cyano (CN) substituted phenyl is selected as the n-type unit and N-phenyl-substituted carbazole as the p-type unit. By adjusting the ortho-, meta-, and para-linking styles of the functional units, the physical parameters are regularly tuned to a large extent. The study of complete spatial separation of frontier molecular orbitals and single-carrier devices confirm the bipolar feature. Blue phosphorescent and thermally activated delayed fluorescence (TADF) OLEDs were fabricated using iridium(iii)bis(4,6-(difluorophenyl)pyridinato-N,C2′)picolinate (FIrpic) and 1,2-bis(carbazol-9-yl)-4,5-dicyanobenzene (2CzPN) as doped emitters. A maximum current efficiency of 46.81 cd A-1 and an external quantum efficiency of 23.14% were achieved for the phosphorescent OLED with the m-CzCN host. Furthermore, high efficiencies of 29.23 cd A-1 and 14.98% were obtained for the 2CzPN based blue TADF device with the o-CzCN host, which are higher than the best literature value of 13.6% for 2CzPN devices. Both m-CzCN and o-CzCN always perform better than p-CzCN. The influence of the chemical structures on their properties and performance is interpreted for these CN-decorated host materials.
- Li, Wei,Li, Jiuyan,Liu, Di,Wang, Fang,Zhang, Shufen
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- COMPOUND, MATERIAL FOR ORGANIC ELECTROLUMINESCENT ELEMENTS, ORGANIC ELECTROLUMINESCENT ELEMENT, AND ELECTRONIC DEVICE
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A compound represented by formula (1) provides an organic electroluminescence device having lifetime further improved: wherein R1 to R9, R11 to R18, R21 to R27, Ar, L1, L2, and L3 are as defined in the description.
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Paragraph 0201; 0203
(2021/04/02)
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- COMPOUND, MATERIAL FOR ORGANIC ELECTROLUMINESCENT ELEMENT, ORGANIC ELECTROLUMINESCENT ELEMENT, AND ELECTRONIC DEVICE
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A compound represented by formula (1): wherein R1 to R7, R11 to R18, L1 to L3, a to c, n, and Ar are as defined in the description, provides an organic electroluminescence device having an emission efficiency and a device lifetime further improved.
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- COMPOUND, MATERIAL FOR ORGANIC ELECTROLUMINESCENCE ELEMENT, ORGANIC ELECTROLUMINESCENCE ELEMENT, AND ELECTRONIC DEVICE
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A novel compound represented by formula (1): wherein R1 to R7, R11 to R18, L1 to L3, a to c, n, and Ar are as defined in the description, provides an organic electroluminescence device having a device lifetime further improved.
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Paragraph 0320; 0322
(2020/02/10)
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- A pyrimidine derivatives and application thereof (by machine translation)
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The invention discloses a pyrimidine derivative and its application, the pyrimidine derivatives having the following -like type (I) indicated by the structure; wherein said R1 , R2 , R3 Are selected from the carbon atom number is 1 - 60 alkyl, substituted and non-substituted aromatic heterocyclic radical, and substituted and non-substituted aromatic ring in base of any one group. The invention through the pyrimidine derivatives key chemical structure and the like is improved, and the pyrimidine derivatives as material is applied to the electro-luminescent layer in the organic electroluminescent device, compared with the prior art can effectively solve the organic electroluminescent device in blue light material of poor stability, low efficiency and the like. (by machine translation)
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Paragraph 0035; 0064; 0076; 0077
(2018/07/30)
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- Synthesis and electroluminescence properties of new blue dual-core OLED emitters using bulky side chromophores
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Using a 1-anthracen-9-yl-pyrene (AP) dual-core emitter, two new emitters of blue light, 1-spiro-9,9′-bifluoren-4-yl-6-(10-spiro-9,9′-bifluoren-4-yl-anthracen-9-yl)-pyrene (DSF-AP) and 1-[2-(9H-carbazol-9-yl)phenyl]-6-[2-(9H-carbazol-9-yl)phenyl-anthracen-9-yl]-pyrene (DCP-AP), were synthesized through boration and the Suzuki aryl-aryl coupling reaction. These two materials exhibited PLmax values at 443?nm and 448?nm in a chloroform solution, and at 458?nm and 463?nm in a thin-film state. EL devices with the synthesized compounds were fabricated in the following configuration: ITO/4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)triphenylamine (2-TNATA) (60?nm)/N,N′-bis (naphthalene-1-yl)-N,N′-bis(phenyl)benzidine (NPB) (15?nm)/synthesized blue light-emitting materials (35?nm)/Tris-(8-hydroxyquinoline)aluminum (Alq3) (20?nm)/lithium fluoride (LiF) (1?nm)/Al (200?nm). Compared with the device made using an AP core lacking side groups, the device made with DCP-AP displayed 31% higher luminance efficiency (resulting in a value of 4.37?cd/A) and 32% higher power efficiency (to yield 1.93?lm/W), as well as a high external quantum efficiency (3.64%).
- Lee, Suji,Kim, Beomjin,Jung, Hyocheol,Shin, Hwangyu,Lee, Hayoon,Lee, Jaehyun,Park, Jongwook
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p. 255 - 261
(2016/09/07)
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- 1, 2, 4-thiadiazole derivatives and their use as electroluminescent materials
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The invention relates to design and synthesis of organic electroluminescence materials which take 1,2,4-thiadiazole electronics transmission groups as a central unit as well as an application of the 1,2,4-thiadiazole electronics transmission groups on an organic electroluminescent device (OLED). The electroluminescent materials take 1,2,4-thiadiazole as a core, groups with different electronic or cavity transmission groups are bonded at positions 3 and 5 sites of 1,2,4-thiadiazole, carrier balance can be effectively solved, exciton recombination with high efficiency is radically realized, thus further combination of high efficiency light-emitting and energy level adjustment of the material can be realized. In addition, the energy level of the compound can be adjusted through an unsymmetrical structure, compared with the electronics transmission groups (such as oxadiazoles, 1,3,5-triazole) in the common main materials, the OLED devices has substantial effects in brightness, efficiency, glass transition temperature and the like, so that the material provided in the invention can be widely applied in the field of organic electroluminescence.
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