Patent ID: 8841653

Claim:
A light-emitting element comprising: an anode; a hole-transport layer over the anode; a first light-emitting layer over and in contact with the hole-transport layer; a second light-emitting layer over and in contact with the first light-emitting layer; and a cathode over the second light-emitting layer, wherein the hole-transport layer includes a first organic compound and an anti-reduction substance, wherein an electron-accepting property of the anti-reduction substance is higher than an electron-accepting property of the first organic compound, wherein the first light-emitting layer includes a first host material having an electron-transport property and a first light-emitting material, wherein the second light-emitting layer includes a second host material having an electron-transport property and a second light-emitting material having a hole-trapping property, wherein the LUMO level of the anti-reduction substance is lower than the LUMO level of the first organic compound and the LUMO level of the first light-emitting layer, and wherein the LUMO level of the first light-emitting layer is lower than the LUMO level of the first organic compound.