Donor or Acceptor: Molecular Engineering Based on dibenzo[a,c]phenazine Backbone for Highly Efficient Thermally-Activated Delayed Fluorescence Organic Light-Emitting Diodes

Liu, Y., Yang, J., Mao, Z., Ma, D., Wang, Y., Zhao, J., Su, S.-J., Chi, Z.,

Adv. Optical Mater. 2023, 2201695

DOI: 10.1002/adom.202201695

The article reports on the development of three thermally-activated delayed fluorescence (TADF) molecules with different donor-acceptor (D-A) frameworks, namely D-A, D-A-D, and D-A-A. The TADF molecules were evaluated for their photophysical and electroluminescence properties. The study found that the TADF molecule with the D-A-A framework achieved the best performance in terms of external quantum efficiency due to its low energy gap between singlet and triplet, effective reverse intersystem crossing, high photoluminescence quantum yield, and horizontal dipole ratio. The study provides insights into the design of efficient TADF emitters.

P-polarized angle-dependent light emissions of CBP doped films were measured by Fluxim using Phelos. Refractive index of the materials was measured by MEL broadband spectroscopic Mueller matrix ellipsometer or extracted by Setfos database. The light out-coupling efficiency of devices was simulated by Setfos.