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Through-space charge transfer hexaarylbenzene dendrimers with thermally activated delayed fluorescence and aggregation-induced emission for efficient solution-processed OLEDs.

ABSTRACT: Through-space electron interaction plays a critical role in determining the optical and charge transport properties of functional materials featuring π-stacked architectures. However, developing efficient organic luminescent materials with such interactions has been a challenge because of the lack of well-established prototypical molecules. Here we report the design of through-space charge transfer hexaarylbenzenes (TSCT-HABs) containing circularly-arrayed electron donors (acridan/dendritic triacridan) and acceptors (triazine), which exhibit both thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) effects for high-efficiency solution-processed organic light-emitting diodes (OLEDs). Spatial separation of donors and acceptors in the TSCT-HABs induces a small singlet-triplet energy splitting of 0.04-0.08 eV, leading to delayed fluorescence with microsecond-scale lifetimes. Meanwhile, the TSCT-HABs display the AIE effect with emission intensity enhanced by 6-17 fold from solution to the aggregation state owing to their propeller-shaped configuration. Solution-processed OLEDs based on the TSCT-HABs show maximum external quantum efficiency up to 14.2%, making them among the most efficient emitters for solution-processed TADF OLEDs.

SUBMITTER: Wang X

PROVIDER: S-EPMC6431955 | biostudies-literature |

REPOSITORIES: biostudies-literature

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