| 摘要 |
PROBLEM TO BE SOLVED: To provide an organic EL element having high emission efficiency and excellent durability.SOLUTION: In an organic EL element comprising at least a light emitting layer sandwiched between a pair of electrodes, the light emitting layer contains at least hole-transporting host material, and electron-transporting phosphorescence luminescent material, and concentration of the electron-transporting phosphorescence luminescent material in the light emitting layer decreases from a cathode side toward an anode side. |
