Semiconductor light emitting device

A semiconductor light emitting device, comprising:

• an n-type semiconductor layer including a nitride semiconductor;
• a p-type semiconductor layer including a nitride semiconductor provided on a [0001]-direction side of the n-type semiconductor layer;
• a light emitting layer provided between the n-type semiconductor layer and the p-type semiconductor layer, the light emitting layer including a plurality of barrier layers of AlxbInybGa1-xb-ybN (0≦xb≦1 and 0≦yb≦1) and a well layer of AlxwInywGa1-xw-ywN (0≦xw≦1, xw≦xb, 0<yw≦1, and yb<yw) provided between the plurality of barrier layers, a bandgap energy of the well layer being less than a bandgap energy of the plurality of barrier layers;
• a first intermediate layer provided between the light emitting layer and the p-type semiconductor layer, the first intermediate layer directly contacting the p-type semiconductor layer, the first intermediate layer including AlxaInyaGa1-xa-yaN (0<xa≦1, xb≦xa, 0≦ya<1, and ya<yw), a bandgap energy of the first intermediate layer being greater than the bandgap energy of the barrier layers;
• and
• a second intermediate layer including a first portion and a second portion, the first portion being in contact with a p-side barrier layer of the plurality of barrier layers most proximal to the p-type semiconductor layer between the first intermediate layer and the light emitting layer, the first portion including Alx1Iny1Ga1-x1-y1N (0<x1≦1, xw<x1, 0<y1<1, and ya<y1<yw), the second portion being in contact with the first intermediate layer between the first portion and the first intermediate layer, the second portion including Alx2Iny2Ga1-x2-y2N (0<x2≦1, xw<x2, 0≦y2<1, and ya≦y2<y1) wherein
• an In composition of the second intermediate layer decreases along a direction from the n-type semiconductor layer toward the p-type semiconductor layer,
• the x2 is within plus or minus 10% of the x1, and
• the x1 and the x2 are within plus or minus 10% of the xa.