Patent ID: 9263693
Filing Date: 2016-02-16
CPC Classification: C09K,H01L

Claim Text:
1. A light-emitting device comprising: a first light-emitting layer over an anode, the first light-emitting layer comprising a first phosphorescent compound, a first organic compound, and a second organic compound; a second light-emitting layer over the first light-emitting layer, the second light-emitting layer comprising a second phosphorescent compound, the first organic compound, and the second organic compound; and a cathode over the second light-emitting layer, wherein an emission spectrum of an exciplex of the first organic compound and the second organic compound overlaps with an absorption corresponding to direct transition from a singlet ground state to a triplet excited state in an absorption spectrum of each of the first phosphorescent compound and the second phosphorescent compound, and wherein the first light-emitting layer comprises a higher proportion of the second organic compound than the second light-emitting layer.