Patent ID: 9373750
Filing Date: 2016-06-21
CPC Classification: H01L

Claim Text:
1. A Group III nitride semiconductor light-emitting device including a light-emitting layer between an n-cladding layer and a p-cladding layer, the light-emitting layer includes a Multi Quantum Well (MQW) structure, wherein the light-emitting layer includes a structure in which a plurality of layer units are continuously and repeatedly deposited, each layer unit consisting of a well layer, a barrier layer having a bandgap larger than a bandgap of the well layer, and an AlGaN layer having an Al composition ratio greater than an Al composition ratio of the barrier layer and formed between the well layer and the barrier layer, the well layer, the AlGaN layer, and the barrier layer being directly in contact with each other, wherein the light-emitting layer comprises two portions of a former portion at an n-cladding layer side and a latter portion at a p-cladding layer side continued to the former portion, the former portion comprising a plurality of repeated first layer units and the latter portion comprising a plurality of repeated second layer units, in which an average Al composition ratio of the AlGaN layers in the former portion is lower than an average Al composition ratio of the AlGaN layers in the latter portion, wherein a disposition order of the well layer, the AlGaN layer, and the barrier layer in said each layer unit is the same between the former portion and the latter portion, wherein the average Al composition ratio of the AlGaN layers in the former portion is 0.2 to 0.8 times the average Al composition ratio of the AlGaN layer in the latter portion, and wherein each of the AlGaN layers in the former portion has a same Al composition ratio, and each of the AlGaN layers in the latter portion has a same Al composition ratio.