Efficient narrow green organic light-emitting diodes with low efficiency roll-offs based on iridium(iii) complexes containing indolo[3,2,1-jk]carbazole and pyrimidine units

Two green Ir( iii ) complexes based on the ligands containing indolo[3,2,1- jk ]carbazole and pyrimidine units show high PLQYs and small FWHMs. The OLEDs show good performances with an EQE max of 31.3% and extremely low efficiency roll-offs.