Patent ID: 11944010
Assignee: KYULUX, INC.
Field: Basic materials chemistry (Chemistry)
Classification: CPC H  C  Y | IPC C  H

Claim 0:
1. An organic electroluminescent device comprising an anode, a cathode, and at least one organic layer including a light emitting layer between the anode and the cathode,
the light emitting layer containing a first organic compound, a second organic compound, and at least one third organic compound that satisfy the following expression (A), the second organic compound being a delayed fluorescent material consisting of the atoms selected from H, D, C, N, O, and S having an energy difference ΔEST between a lowest singlet excited state and a lowest triplet excited state at 77K of 0.3 eV or less, the third organic compound being a light emitting material, and the third organic compound is excited to the singlet excited state by accepting energy from the second organic compound in the singlet excited state:

ES1(A)>ES1(B)>ES1(C)  (A), wherein ES1 (A) represents a lowest singlet excitation energy level of the first organic compound; ES1 (B) represents a lowest singlet excitation energy level of the second organic compound; and ES1 (C) represents a lowest singlet excitation energy level of the third organic compound.