Patent ID: 7825428

Claim:
A GaN-based semiconductor light emitting device comprising: a substrate; and an n-type GaN-based semiconductor layer, an active layer and a p-type GaN-based semiconductor layer sequentially deposited on the substrate, wherein the active layer includes: a first barrier layer formed on the n-type GaN-based semiconductor layer and comprising Al x In y Ga 1−x−y N, where 0<x<1, 0<y<1, and 0<x+y<1; a second barrier layer formed on the first barrier layer and having an energy band higher than an energy band of the first barrier layer, the second barrier layer comprising one of In x Ga 1−x N, where 0<x<0.2, and GaN; a well layer formed on the second barrier layer and comprising In x Ga 1−x N, where 0<x<1; a third barrier layer formed on the well layer and comprising one of In x Ga 1−x N, where 0<x<0.2 and GaN; and a lattice mismatch relaxation layer formed on the third barrier and comprising one of Al x In y Ga 1−x−y N, where 0<x<1, 0<y<1, and 0<x+y<1, Al x Ga 1−x N, where 0<x<1, and GaN, the lattice mismatch relaxation layer having a lattice constant greater than a lattice constant of the well layer and smaller than a lattice constant of the p-type GaN-based semiconductor layer.