摘要 |
PROBLEM TO BE SOLVED: To provide an organic electroluminescent device having a high light emission efficiency.SOLUTION: In an organic electroluminescent device, a 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.) |