Novel carbazole derivatives designed by an ortho-linkage strategy for efficient phosphorescent organic light-emitting diodes
| Autor: | Danli Zhao, Hui-Ting Ge, Jian Fan, Liang-Sheng Liao, Xiang-Yang Liu, Yue Zhao |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Dopant Carbazole chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention chemistry.chemical_compound chemistry law Polymer chemistry Materials Chemistry OLED Phosphorescent organic light-emitting diode Iridium 0210 nano-technology Phosphorescence Benzene Diode |
| Zdroj: | Journal of Materials Chemistry C. 6:4300-4307 |
| ISSN: | 2050-7534 2050-7526 |
| DOI: | 10.1039/c8tc00630j |
| Popis: | Two novel carbazole derivatives 2′-(9H-carbazol-9-yl)-[1,1′-biphenyl]-4-carbonitrile (CNPhCz) and 2′-(9H-carbazol-9-yl)-[1,1′:3′,1′′-terphenyl]-4,4′′-dicarbonitrile (DCNPhCz) were designed and prepared as host materials for phosphorescent organic light-emitting diodes (PHOLEDs). CNPhCz and DCNPhCz were synthesized by an ortho-linkage strategy. In CNPhCz, one cyanophenyl and one carbazole unit were attached to the central benzene ring at the neighboring positions, while in DCNPhCz the carbazole group was surrounded by two cyanophenyl groups. The influence of different numbers of electron-withdrawing groups in these host materials on the charge-transport behavior and OLED device performance was studied systematically. Blue and green PHOLEDs based on these hosts were fabricated using common device structures with bis(4,6-(difluorophenyl)pyridinato-N,C2′)picolinate iridium(III) (FIrpic) and bis(2-phenylpyridine) (acetylacetonate)iridium(III) (Ir(ppy)2(acac)) as the dopants, respectively. The results indicated that the material with a smaller number of electron-withdrawing cyanobenzene groups (CNPhCz) showed better green PHOLED device performance with maximum efficiencies of 88.0 cd A−1, 86.1 lm W−1 and 24.4%. |
| Databáze: | OpenAIRE |
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