A novel molecular design featuring the conversion of inefficient TADF emitters into efficient TADF emitters for deep-blue organic light emitting diodes

In this report, we unveiled a new molecular design featuring the transformation of inefficient thermally activated delayed fluorescence (TADF) emitters into the efficient TADF emitters by combing them with non-TADF type chromophore units to develop deep-blue TADF emitters for organic light-emitting diodes. The inefficient TADF emitter and non-TADF chromophore were connected directly through a phenyl linker in a sterically hindered configuration by selectively interlocking two donors in the backbone structure. The new TADF emitter demonstrated excellent device performances with maximum external quantum efficiency up to 22% and y color coordinate of 0.15. Based on these results, we believe that the proposed new design strategy is effective with regard to the conversion of inefficient deep-blue TADF emitters to efficient deep-blue TADF emitters and can be diversely applied for the development of efficient TADF emitters.