Patent ID: 7439546

Claim:
A semiconductor light emitting device comprising: an active layer made of a first nitride III-V compound semiconductor containing In and Ga; an intermediate layer in contact with the active layer and made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor; an optical guide layer in contact with the intermediate layer and made of a third nitride III-V compound semiconductor containing Ga; a cap layer in contact with the optical guide layer and made of a fourth nitride III-V compound semiconductor containing Al and Ga; and a p-type clad layer in contact with the cap layer and made of a fifth nitride III-V compound semiconductor containing Al and Ga and different from the fourth nitride III-V compound semiconductor, wherein the cap layer at all points has a band gap larger than that of the p-type clad layer.