The application belongs to the field of organic electroluminescent materials, and particularly discloses a
boron-containing
multiple resonance type thermally activated delayed
fluorescence material and an organic electroluminescent device. The material adopts a single spiro carbon locking structure, restricts MR mother
nucleus conformation vibration by means of a spiro carbon covalent bridge, suppresses
excited state relaxation, narrows a spectrum, reduces non-
radiation transition, and improves
fluorescence quantum efficiency. A vertical three-dimensional spiro ring generates steric hindrance, suppresses intermolecular π-π stacking, relieves aggregation and
concentration quenching, and is suitable for wide
doping concentration. The spiro carbon condensed ring improves the
thermal stability of the molecule, prevents film
crystallization and phase separation, improves the stability of the film layer, and prolongs the service life of the device. Compared with a double spiro carbon structure, the single spiro carbon breaks the center symmetry of the mother
nucleus, realizes asymmetric separation of the front orbital, reduces the single triplet
energy level difference, accelerates the reverse
intersystem crossing, and improves the device efficiency and service life under large current.