| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting element having high external quantum efficiency, and to provide a light-emitting element having a long service life.SOLUTION: The light-emitting element has a light-emitting layer between an anode and a cathode. The light-emitting layer is a laminate comprising: a first light-emitting layer which contains at least a first luminescent substance for converting triplet excitation energy into light emission, a first organic compound having electron transportability, and a second organic compound having hole transportability and is formed on the anode side; and a second light-emitting layer which is formed containing at least a second luminescent substance for converting triplet excitation energy into light emission, the first organic compound, and a third organic compound having hole transportability. The second organic compound has a lower HOMO level than the third organic compound. The first luminescent substance exhibits light emission of a shorter wavelength than the second luminescent substance. A combination of the first organic compound and the second organic compound and a combination of the first organic compound and the third organic compound each form an excited complex. |
