Patent ID: 9391289
Filing Date: 2016-07-12
CPC Classification: C07F,C09K,H01L

Claim Text:
1. A light-emitting device comprising: a first electroluminescent layer over an anode, and a second electroluminescent layer over the first electroluminescent layer, at least one of the first electroluminescent layer and the second electroluminescent layer comprising a first light-emitting layer and a second light-emitting layer over the first light-emitting layer; and a charge generation layer between the first electroluminescent layer and the second electroluminescent layer, the charge generation layer being configured to inject electrons into the first electroluminescent layer and inject holes into the second electroluminescent layer, a cathode over the second electroluminescent layer, wherein the first light-emitting layer comprises a first phosphorescent compound, a first organic compound having an electron-transport property, and a second organic compound having a hole-transport property, wherein the second light-emitting layer comprises a second phosphorescent compound and the first organic compound, wherein the first phosphorescent compound is not the same compound as the second phosphorescent compound, and wherein an emission spectrum of an exciplex of the first organic compound and the second organic compound overlaps with an absorption spectrum of the first phosphorescent compound.