Patent ID: 8274069

Claim:
A nitride semiconductor light emitting device comprising: an n-type nitride semiconductor layer provided on a substrate; an active layer provided on the n-type nitride semiconductor layer, and including quantum barrier layers and a plurality of quantum well layers; and a p-type nitride semiconductor layer provided on the active layer, wherein each of the quantum barrier layers comprises two In x Ga (1-x) N layers (0<x<1) having energy band gaps larger than the quantum well layers and at least three Al y Ga (1-y) N layers (0≦y<1) having energy band gaps larger than the two In x Ga (1-x) N layers, the at least three Al y Ga (1-y) N layers is are stacked between the two In x Ga (1-x) N layers and the two In x Ga (1-x) N layers are outermost layers of each of the quantum barriers and are adjacent to two of the plurality of quantum well layers and wherein the plurality of quantum well layers are formed of In z Ga (1-z) N (0<x<z<1), each of the two In x Ga (1-x) N layers and the at least three Al y Ga (1-y) N layers forming the quantum barrier layer has a thickness of 0.5 to 10 nm, and a first one of the at least three Al y Ga (1-y) N layers has a larger bandgap than that of a second one of the at least three Al y Ga (1-y) N layers that is closer to the quantum well layers than the first one of the at least three Al y Ga (1-y) N layers.