High-efficiency thermally activated delayed fluorescence materials via a shamrock-shaped design strategy to enable OLEDs with external quantum efficiency over 38%

Li, G., Pu, J., Yang, Z., Deng, H., Liu, Y., Mao, Z., Zhao, J., Su, S., Chi, Z., Aggregate 2023, 00, e382.

https://doi.org/10.1002/agt2.382

This study proposes a design strategy for constructing highly efficient organic light-emitting diodes (OLEDs) using thermally activated delayed fluorescence (TADF) emitters with high horizontal dipole ratios. The researchers designed two TADF emitters, BO-3DMAC and BO-3DPAC, using a shamrock-shaped structure. These emitters exhibited high horizontal dipole ratios of 84-93% in both neat and doped films. The emitters showed excellent external quantum efficiencies (EQEs) of up to 38.7% in doped OLEDs with sky-blue emission. The researchers also demonstrated that the shamrock-shaped design resulted in aggregation-induced emission (AIE) and low efficiency roll-off. The emitters had low singlet-triplet energy splitting (ΔEst) and achieved high PLQYs. The results highlight the potential of the shamrock-shaped design to construct TADF emitters with high Θ// and pave the way for the development of high-performance OLEDs.

How Setfos was used

The refractive index of the materials were extracted from the Setfos database and the light out-coupling efficiency of devices were also simulated.