| 초록 |
Recently, phosphorescent organic light-emitting diodes (PhOLEDs) have received a great attention because they can harvest singlet and triplet exciton. If the HOMO energy level of ETL is higher than that of EML, the hole can be migrated into ETL. In addition, if the triplet energy is lower than that of EML, the ETL can quench the triplet energy. In order to confine the hole and triplet exciton in the EML, HBMs having a high triplet energy and deep HOMO energy level must be introduced between the EML and ETL. Furthermore, it is well known that low Tg value of OLED materials tend to shorten the device lifetime due to thin film crystallization during OLED driving. In this work, we designed and synthesized two HBMs using pyrimidine and phenylene segments. The thermal and optical, electrochemical, and electron-transporting characteristics of two materials were investigated by using TGA, DSC, UV-Vis spectroscopy, CV, and EOD. The device performance based on new HBMs will be presented. |
