Patent ID: 9082994
Filing Date: 2015-07-14
Classification: C09K,H01L

Abstract:
1. A light-emitting device comprising: a first electrode; a light-emitting layer over the first electrode, the light-emitting layer comprising a host material, a first guest material, and a second guest material; and a second electrode over the light-emitting layer, wherein the light-emitting layer comprises a first light-emitting layer and a second light-emitting layer which are in contact with each other, wherein the host material and the first guest material are included in the first light-emitting layer, wherein the host material and the second guest material are included in the second light-emitting layer, wherein a T1 level of the host material is lower than a T1 level of the first guest material and higher than a T1 level of the second guest material, and wherein a difference in T1 level between the host material and the first guest material is larger than 0 eV and less than or equal to 0.2 eV.