TADF Organic Electroluminescent Compound for OLED Efficiency

The patent introduces thermally activated delayed fluorescence (TADF) compounds with specific molecular structures containing electron-donating and electron-withdrawing groups. By changing the chemical parameters and molecular architecture of the electroluminescent compounds, the patent achieves efficient carrier transport and high light-emitting efficiency while managing the complexity through targeted molecular design rather than systematic complexity increase

The patent employs composite molecular structures combining electron-donating groups (such as carbazole, triphen胺) and electron-withdrawing groups (such as pyridine, pyrimidine) to create TADF compounds. These composite materials enable both efficient carrier transport and radiative decay, resolving the contradiction between efficiency improvement and structural complexity by integrating multiple functional groups into a unified molecular system

The patent utilizes thermally activated delayed fluorescence (TADF) mechanism where thermal energy normally causing degradation is converted into a beneficial process for population transfer between singlet and triplet sublevels. This converts the harmful thermal effects into a useful mechanism for achieving higher energy excitation states with reduced degradation, as the TADF pathway provides an efficient route for carrier transport and radiative decay that mitigates degradation

The patent changes the energy level parameters and molecular structure parameters of the electroluminescent compounds to enable TADF with optimized singlet-triplet energy gaps. By carefully tuning these parameters, the patent achieves higher brightness through higher energy excitation states while the TADF mechanism simultaneously reduces degradation by providing efficient non-radiative and radiative decay pathways that prevent accumulation of harmful excited states