Patent ID: 8530908
Filing Date: 2013-09-10
Classification: H01L

Abstract:
1. An organic EL element comprising: an organic EL layer including a transparent electrode, a reflective electrode, and a light-emitting layer disposed between the transparent electrode and the reflective electrode; a transparent layer disposed on a light-exiting side of the transparent electrode; and a light extraction structure disposed on a light-exiting side of the transparent layer and having a protruding shape with inclined portions that are gradually narrowing from the transparent layer side, wherein the transparent layer and the light extraction structure have a larger refractive index than the light-emitting layer, and wherein the inclined portions of the light extraction structure are designed so as to satisfy at least one of Condition 1 and Condition 2 for extracting guided wave light emitted from the light-emitting layer and incident on the light extraction structure from the light extraction structure to the outside of the organic EL element, in a cross section taken along a plane perpendicular to the reflective electrode, where two inclination angles φ Condition 1 is given by and Condition 2 is given by wherein n 0 denotes the refractive index of the outer area of the organic EL element, n 1 denotes the refractive index of the light-emitting layer, n 2 denotes the refractive index of the light extraction structure, θ 1 and θ 3 denote the angles formed between the guided wave light and the normal to the reflective electrode in the light-emitting layer, and θ 2 and θ 4 denote the angles formed between the guided wave light and the normal to the reflective electrode in the light extraction structure.