abstract |
The present invention relates to organic light emitting elements, comprising thermally activated delayed fluorescence (TADF) emitters and/or hosts of formula (I), which have a sufficiently small energy gap between S 1 and T 1 (ΔE ST ) to enable up-conversion of the triplet exciton from T 1 to S 1 . The organic light emitting elements show high electroluminescent efficiency. |