Patent ID: 8324615
Filing Date: 2012-12-04
Classification: H01L

Abstract:
1. A light-emitting element comprising: a first electrode; a first light-emitting layer formed over the first electrode; a second light-emitting layer formed on and in contact with the first light-emitting layer; and a second electrode formed over the second light-emitting layer, wherein the first light-emitting layer includes a first light-emitting substance and a hole-transporting organic compound, wherein the second light-emitting layer includes a second light-emitting substance and an electron-transporting organic compound, wherein a difference in highest occupied molecular orbital levels between the hole-transporting organic compound, the first light-emitting substance, and the second light-emitting substance is less than or equal to 0.2 eV, and wherein the hole-transporting organic compound includes an arylamine skeleton and does not include a tricyclic, teracyclic, pentacyclic, or hexacyclic aromatic hydrocarbon skeleton.