Bis(phenanthroimidazolyl)biphenyl derivatives as saturated blue emitters for electroluminescent devices
作者:Chun-Jung Kuo、Ting-Yu Li、Chia-Chun Lien、Charng-Hsing Liu、Fang-Iy Wu、Min-Jie Huang
DOI:10.1039/b816327h
日期:——
Blue-emitting bis(phenanthroimidazolyl)biphenyl derivatives, 4,4′-bis(1-phenyl-1H-phenanthro[9,10-d]phenanthroimidazolyl-2-yl)biphenyl (PPIP), 4,4′-bis(1-p-tolyl-1H-phenanthro[9,10-d]phenanthroimidazolyl-2-yl)biphenyl (TPIP) and 4,4′-bis(1-p-anisyl-1H-phenanthro[9,10-d]phenanthroimidazolyl-2-yl)biphenyl (APIP) were effectively synthesized in high yields from commercially available starting materials through a simple two-step procedure without using expensive noble-metal catalysts. These compounds showed excellent thermal properties with a very high glass-transition temperature of 197–200 °C and emitted intense blue light in solution with emission peaks at ca. 428 and 446 nm. By using a different hole-transporting layer, we optimized the electroluminescent efficiencies of the PPIP-based devices. All the PPIP-based devices were turned on at very low applied voltages of <3.0 V and gave pure-blue light with a Commission Internationale d'Énclairage y-coordinate value (CIEy) ≤ 0.15. Among them, device C using TCTA (4,4′,4″-tris(N-carbazolyl)triphenylamine) as the hole-transporting layer reached a very high external quantum efficiency of 6.31% and power efficiency of 7.30 lm/W. When using TPIP or APIP as the emissive layer to replace PPIP in the optimal device C, the resulting devices also exhibited very high external quantum efficiencies of more than 5%, and highly saturated blue light can be obtained from the TPIP-based device with CIEy ≤ 0.10.
发蓝光的双(菲并咪唑基)联苯衍生物,4,4′-双(1-苯基-1H-菲[9,10-d]菲并咪唑基-2-基)联苯(PPIP),4,4′-双(1 -对甲苯基-1H-菲并[9,10-d]菲并咪唑基-2-基)联苯 (TPIP) 和 4,4′-双(1-对茴香基-1H-菲[9,10-d]菲并咪唑基不使用昂贵的贵金属催化剂,通过简单的两步程序,以市售原材料为原料,以高产率有效合成了-2-基)联苯(APIP)。这些化合物表现出优异的热性能,具有 197-200 °C 的极高玻璃化转变温度,并在溶液中发出强烈的蓝光,发射峰约为 100°C。 428 和 446 纳米。通过使用不同的空穴传输层,我们优化了基于 PPIP 的器件的电致发光效率。所有基于 PPIP 的设备均在 <3.0 V 的极低施加电压下开启,并发出纯蓝光,国际委员会 y 坐标值 (CIEy) ≤ 0.15。其中,采用TCTA(4,4′,4″-三(N-咔唑基)三苯胺)作为空穴传输层的器件C达到了6.31%的极高外量子效率和7.30 lm/W的功率效率。当在最佳器件C中使用TPIP或APIP作为发射层代替PPIP时,所得器件还表现出超过5%的非常高的外量子效率,并且可以从具有CIEy的基于TPIP的器件获得高度饱和的蓝光≤0.10。