A novel compound (BCBP) based on the modification of a well-known host material 4,4â²-(bis(9-carbazolyl))biphenyl (CBP) through arylmethylene bridge linkage was synthesized, and fully characterized. Its thermal, electrochemical, electronic absorption and photoluminescent properties were studied. A high glass transition temperature (Tg) of 173 °C is observed for BCBP due to the introduction of the bridged structure, remarkably contrasting with a low Tg of 62 °C for CBP. Furthermore, the bridged structure enhances the conjugation and raises the HOMO energy, thus facilitating hole-injection and leading to a low turn-on voltage in an electroluminescent device. With the device structure of ITO/MoO3/NPB/Ir complex: BCBP/BCP/Alq3/LiF/Al, maximum power efficiencies of 41.3 lm/W and 6.3 lm/W for green- and blue-emitting OLED were achieved, respectively.
通过芳基亚甲基桥连接,对一种广为人知的基质材料4,4-(双(9-
咔唑基))
联苯(CBP)进行了改性,合成了一种新型化合物(BCBP),并对其进行了充分表征。对其热学、电
化学、电子吸收和光致发光特性进行了研究。由于引入了桥接结构,BCBP具有173°C的高
玻璃化转变温度(Tg),与CBP的62°C低Tg形成鲜明对比。此外,桥接结构增强了共轭作用,提高了HOMO能量,从而促进了空穴注入,并降低了电致发光器件的开启电压。在ITO/
MoO3/NPB/Ir复合器件结构中:BCBP/
BCP/Alq3/
LiF/Al,绿色和蓝色发光OLED的最大功率效率分别达到41.3 lm/W和6.3 lm/W。