초록 |
We investigate the dissociation mechanism of the C–N bond in the tris(4-carbazoyl-9-ylphenyl)amine (TCTA) which is a blended Thermally Activated Delayed Fluorescence host material in organic light-emitting diodes (OLEDs). The C–N bond dissociation energies, calculated at the density functional theory level, are found to depend strongly on the charge states of the parental molecules. In particular, the anionic C–N bond dissociations resulting low dissociation energies. These low values are attributed to the large electron affinity, a feature that importantly can be modulated via substitution. The implications of this result must be considered when designing blue OLED hosts since these materials must combine chemical stability and high triplet energy. |