The invention belongs to the technical field of application of photoelectric materials and particularly relates to a thermally activated delayed fluorescent material, a preparation method therefor andan application of the thermally activated delayed fluorescent material. According to the thermally activated delayed fluorescent material, the preparation method therefor and the application of the thermally activated delayed fluorescent material, the thermally activated delayed fluorescent material is formed through introducing a phenyl bridge between a donor fragment and a
receptor fragment oronto a donor /
receptor fragment, the PI conjugation degree of the thermally activated delayed fluorescent material is extended, the distance of separated electrons is enlarged, the
energy loss of a triplet-charge reaction is avoided due to a material delocalization effect design, and device efficiency roll-off is improved through regulating and controlling an
exciton transition angle. When the thermally activated delayed fluorescent material is applied to a device as a luminescent layer object material or a light outlet layer material, blue shift of luminescent
wavelength will be caused by N substitution on donor /
receptor fragments, the
electron withdrawing capability of
diphenyl sulfide sulfone is weakened, widening of energy gaps is facilitated, and
deep blue light is achieved; and object-to-subject triplet energy
backflow can be effectively inhibited by a triplet
energy level lower than that of a subject material, so that triplet excitons are confined into a luminescent layer, the light withdrawing efficiency is increased, and thus, the thermally activated delayed fluorescent material is an ideal luminescent layer object material or light outlet layer material.