| 摘要 |
PROBLEM TO BE SOLVED: To provide an organic electroluminescent device having a high light emission efficiency.SOLUTION: An organic electroluminescent device comprises: an anode; a cathode; and a light-emitting layer between the anode and the cathode. The light-emitting layer includes at least a first organic compound, a second organic compound and a third organic compound and satisfies the formula (A) below. The second organic compound is a delay fluorescent material, and the third organic compound is a light emitter. Formula (A): E(A)>E(B)>E(C) (where E(A), E(B) and E(C) represent minimum excited singlet energy levels of the first to third organic compounds respectively.) |
