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

OLEDs based on iridium(iii) complexes containing an indolo[3,2,1-jk]carbazole unit exhibit good emission performances with a narrow full width at half maximum of 33 nm, good efficiency and low efficiency roll-off.