Key points are not available for this paper at this time.
Abstract Thermally activated delayed fluorescence (TADF) emitters featuring preferential horizontal emitting dipole orientation (EDO) are in urgent demand for enhanced optical outcoupling efficiency in organic light‐emitting diodes (OLEDs). However, simultaneously manipulating EDO and optoelectronic properties remains a formidable challenge. Here, an extended linear D–A–D structure with both enlarged donor (D) and acceptor (A) π‐systems is established, not only elaborately manipulating parallel horizontal molecular orientation and EDO along its long axis by multi‐driving‐forces for a high horizontal dipole ratio ( Θ // ), but also delocalizing distribution of frontier energy levels for optimized electronic properties. The proof‐of‐the‐concept emitter simultaneously affords a high Θ // of 92%, a high photoluminescence quantum yield of 95%, and a fast reverse intersystem crossing rate of 1.16 × 10 6 s ‐1 . The corresponding OLED achieves a champion maximum external quantum efficiency of 39.1% among all green TADF devices without any external light‐extraction techniques, together with a maximum power efficiency of 112.0 lm W ‐1 and alleviated efficiency roll‐off. These findings may inspire even better full‐color TADF emitters that push the device efficiency toward the theoretical limits.
Yang et al. (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: