Patent ID: 9337438
Filing Date: 2016-05-10
CPC Classification: H01L

Claim Text:
1. A light-emitting element comprising: an EL layer between an anode and a cathode, wherein the EL layer comprises a first layer including a hole-injecting property, a second layer including a hole-transporting property, a third layer including a light-emitting property, and a fourth layer controlling transport of electrons, wherein the first layer and the second layer are interposed between the anode and the third layer, wherein the fourth layer is interposed between the cathode and the third layer, wherein the fourth layer comprises a first organic compound including an electron-transporting property and a second organic compound including a hole-transporting property, wherein an absolute value of a highest occupied molecular orbital level of the second layer is larger than an absolute value of a highest occupied molecular orbital level of the first layer, wherein the third layer is in direct contact with the second layer and the fourth layer, wherein the third layer comprises a third organic compound and a light-emitting material, wherein the light-emitting material is a phosphorescent material, wherein the second organic compound is a red phosphorescent material, wherein a difference between a peak value of an emission spectrum of the second organic compound and a peak value of an emission spectrum of the light-emitting material is within 30 nm, and wherein the light-emitting material is different from the second organic compound.