Patent ID: 8106581

Claim:
An organic electroluminescence element comprising an organic layer comprising a light-emitting layer disposed between a pair of electrodes, wherein the light-emitting layer comprises at least one hole-transporting light-emitting material and at least one electron-transporting host material, and a concentration of the hole-transporting light-emitting material in the light-emitting layer decreases from an anode side toward a cathode side; wherein the at least one hole-transporting light-emitting material and the at least one electron-transporting host material are simultaneously present at the entire light-emitting layer, and a concentration of the at least one hole-transporting light-emitting material decreases from an anode side toward a cathode side within the entire light-emitting layer at which the at least one hole-transporting light-emitting material and the at least one electron-transporting host material are simultaneously present; and wherein a ratio of the concentration of the hole-transporting light-emitting material in an interface region of the entire light-emitting layer on the cathode side relative to the concentration of the hole-transporting light-emitting material in an interface region of the entire light-emitting layer on the anode side (concentration of hole-transporting light-emitting material in interface region on cathode side/concentration of hole-transporting light-emitting material in interface region on anode side) is from 0% to 30%.