Patent ID: 8729575

Claim:
A semiconductor light emitting device comprising: an N-type nitride semiconductor layer; an active layer of a nitride semiconductor disposed on the N-type nitride semiconductor layer; and a P-type nitride semiconductor layer disposed on the active layer, wherein the P-type nitride semiconductor layer includes a first aluminum gallium nitride layer, an indium concentration in the first aluminum gallium nitride layer is between 1E18 atoms/cm 3 and 1E20 atoms/cm 3 inclusive, a carbon concentration is equal to or less than 6E17 atoms/cm 3 , a magnesium concentration is between 5E18 atoms/cm 3 and 3E19 atoms/cm 3 inclusive, and Y>{(−5.35e19) 2 −(X−2.70e19) 2 } 1/2 −4.63e19 holds, where X and Y denote a magnesium concentration and an acceptor concentration respectively in the aluminum gallium nitride layer.