Patent ID: 8431940
Filing Date: 2013-04-30
Classification: H01L

Abstract:
1. A light emitting element comprising: an anode; a first EL layer over the anode, the first EL layer comprising a first material having an electron-transporting property; a first layer over the first EL layer; a second layer over and in contact with the first layer; a region over and in contact with the second layer; a second EL layer over the region; and a cathode over the second EL layer, wherein the first layer includes at least one selected from the group consisting of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, and a rare earth metal compound, wherein the second layer includes a second material having an electron-transporting property, wherein the region includes a material having a hole-transporting property and an acceptor material, and wherein the first material is different from the second material.