Patent ID: 8564195
Filing Date: 2013-10-22
Classification: H01L

Abstract:
1. A display device comprising: a first electrode; a second electrode; and a light emitting material layer interposed between the first electrode and the second electrode, the light emitting material layer being doped with an electric charge transport material having a content which varies along a thickness direction of the layer, the emitting material layer comprising a plurality of sub-layers stacked in a sequence, wherein at least one of the sub-layers comprises: a pair of first regions doped with the electric charge transport material to a first content; and a second region doped with the electric charge transport material to a second content lower than the first content, wherein the second region is positioned between the pair of first regions, wherein at least another one of the sub-layers comprises: a third region doped with the electric charge transport material to a third content, wherein the third region is positioned outside the first region; a fourth region doped with the electric charge transport material to a fourth content lower than the third content and the first content, wherein the fourth region is positioned outside the third region, wherein the fourth region is placed in an outmost part of the emitting material layer, the third region is doped with a same electric charge transport material as the fourth region.