| abstract |
The present invention discloses a condensed polycyclic compound. It has the structure according to formula (I) or formula (II). In the condensed polycyclic compound, more balanced electron conduction behavior besides improved property of the holes is achieved by controlling an effective conjugation of an aromatic ring and a heterocycle. Such a compound has a high triplet energy level and a high glass transition temperature and its material molecules are not easy to crystallize, so that it can ensure efficient energy transfer to a guest material as the host material of a light-emitting layer. By adjusting the substituted group of the condensed polycyclic compound, the electron and hole conduction behavior is further improved, the difference between the singlet and triplet energy levels is reduced, the charge carrier recombination range is expanded and exciton annihilation in the triplet state is prevented. The present invention further discloses an organic electroluminescent device. At least one functional layer contains the condensed polycyclic compound, which serves as the host material of the light-emitting layer and is matched to the energy level of an adjacent charge carrier conduction layer, which, in addition to increased light emission efficiency of the device, reduces the drive voltage of the device. |