THERMALLY-ACTIVATED SENSITIZED PHOSPHORESCENT ORGANIC ELECTROLUMINESCENT DEVICE

摘要

A thermally-activated sensitized phosphorescent organic electroluminescent device comprises a luminescent layer (06). Main materials of the luminescent layer (06) consist of two materials. One of the two materials is a hole transmission material, and the other of the two materials is an electronic transmission material. At least one the two materials is a thermal activation delayed fluorescence material. The main materials are doped with a phosphorescence dye. The proportion of the phosphorescence dye in the luminescent layer is less than 15% by weight. The triplet-state level of a CT excited state of the thermal activation delayed fluorescence material is higher than the triplet-state level of an n-π excited state, and a difference ranges from 0 eV to 0.3 eV; or the triplet-state level of the CT excited state of the thermal activation delayed fluorescence material is higher than the triplet-state level of the n-π excited state, and the difference is higher than 1.0 eV, and a difference between a second triplet-state level of the n-π excited state and a first singlet-state level of the CT excited state ranges from -0.1 eV to 0.1 eV.