Thermally activated delayed fluorescence molecules, materials comprising said molecules, and devices comprising said materials

摘要

A thermally activated delayed fluorescence (TADF) molecule comprising: a central electron donor moiety, wherein the central electron donor moiety is formed of a conjugated multi-ring system comprising three nitrogen atoms; and three electron acceptor moieties, each bonded to the central electron donor moiety via one of the three nitrogen atoms, wherein at least one of the three electron acceptor moieties is twisted relative to the central electron donor moiety defining a torsion angle in a range 40° to 90° whereby the TADF molecule has a photoluminescence quantum yield of 60% and a rate of reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state of at least 1×10 s−1.