Patent ID: 7547909

Claim:
A III-nitride compound semiconductor light emitting device comprising an active layer with the multi-quantum wells interposed between an n-In x Al y Ga z N (x+y+z=1, 0≦x<1, 0≦y<1, 0<z≦1)layer and a p-In x Al y Ga z N(x+y+z=1, 0≦x<1, 0≦y<1, 0<z≦1) layer, wherein the active layer comprises an alternate stacking of a quantum-well layer made of In x Ga 1-x N(0.05<x<1) and a sandwich barrier layer, the sandwich barrier layer comprising a first outer barrier layer of In a Ga 1-a N(0<a≦0.05), a middle barrier layer of Al y Ga 1-y N(0≦y<1) formed on the first outer barrier layer and a second outer barrier layer of In b Ga 1-b N(0<b≦0.05) formed on the middle barrier layer, and wherein the middle barrier layer has a bandgap energy greater than those of the first and second outer barrier layers.