Patent ID: 8759853

Claim:
A light emitting device comprising: a substrate; a first buffer layer disposed on the substrate, the first buffer layer comprising aluminum nitride (AlN); an insertion layer disposed on the first buffer layer, the insertion layer comprising aluminum (Al); a light emitting structure disposed on the insertion layer, the light emitting structure comprising a first semiconductor layer, a second semiconductor layer, and an active layer interposed between the first semiconductor layer and the second semiconductor layer; and a second buffer layer that is interposed between the insertion layer and the light emitting structure and comprising aluminum nitride (AlN), wherein the insertion layer comprises at least one first layer and at least one second layer, and wherein the first layer contains aluminum gallium nitride (Al x Ga 1-x N, 0.3≦x≦0.4), and the second layer comprises aluminum gallium nitride (Al y Ga 1-y N, 0.05≦y≦0.1).