Efficient deep blue fluorescent OLEDs with ultra-low efficiency roll-off based on 4H-1,2,4-triazole cored D-A and D-A-D type emitters

The non-doped OLEDs exhibited fantastic performances with maximum EQE of 6.3% and CIE coordinates of (0.161, 0.034) as well as demonstrated ultra-low efficiency roll-off.229