New Bipolar Green Host Materials Containing Benzimidazole-Carbazole Moiety in Phosphorescent OLEDs
作者:Jung-Hwan Park、Eun-Kyung Kim、Ibrahim M. El-Deeb、Su-Jin Jung、Dae-Hyuk Choi、Dong-Ha Kim、Kyung-Ho Yoo、Jang-Hyuk Kwon、So-Ha Lee
DOI:10.5012/bkcs.2011.32.3.841
日期:2011.3.20
New green host materials, 9-phenyl-3-(4-(1-phenyl-1H-benzo[d] imidazol-2-yl)phenyl)-9H-carbazole (3a) and 9-(naphthyl-2-yl)-3-(4-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl)-9H-carbazole (3b), have been designed and synthesized by attaching the electron transporting benzimidazole moiety to the hole transporting carbazole unit. These compounds have similar HOMO, LUMO levels and band-gap characteristics compared with CBP (4,4'-di(N-carbazolyl)biphenyl). The fabricated green phosphorescent OLED with this 3a host shows much better device performances compared to CBP-based one. The current and power efficiency is enhanced at least by 60 percent at a given constant luminance of 1000 cd/$m^2$.
通过将传输电子的苯并咪唑分子连接到传输空穴的咔唑单元上,设计并合成了新型绿色宿主材料--9-苯基-3-(4-(1-苯基-1H-苯并[d]咪唑-2-基)苯基)-9H-咔唑(3a)和 9-(萘基-2-基)-3-(4-(1-苯基-1H-苯并[d]咪唑-2-基)苯基)-9H-咔唑(3b)。与 CBP(4,4'-二(N-咔唑基)联苯)相比,这些化合物具有相似的 HOMO、LUMO 水平和带隙特性。与基于 CBP 的绿色磷光 OLED 相比,使用这种 3a 主化合物制造的绿色磷光 OLED 显示出更好的器件性能。在给定的 1000 cd/$m^2$ 恒定亮度下,电流和功率效率至少提高了 60%。