C.-J. Zheng, C.-S. Lee, X.-H. Zhang, and co-workers design three novel exciplex emitters by mixing three hole-transporting arylamines with a high triplet energy bipolar host as shown on page 2378. The best exciplex-based organic light-emitting device shows strong thermally activated delayed fluorescence and realizes a high external quantum efficiency of 15.4%. In particular, strategies for predicting and designing efficient exciplex emitters are demonstrated to achieve efficient TADF exciplex emitters. Advanced Materials, 2015 |