Semiconductor light emitting device

A semiconductor light emitting device comprising:

• a nitride semiconductor substrate having, as a principal plane, a plane inclined from a c-plane in an m-axis direction in a range from 60° to 90° both inclusive;
• an underlayer provided on the nitride semiconductor substrate and including a first layer and a second layer that are stacked on each other, the first layer including Alx2Inx1Ga(1-x1-x2)N (0<<x1<1, 0≤x2<1) and having a dislocation along an intersection line of the principal plane of the nitride semiconductor substrate and a (1-100) plane, the second layer including Aly2Iny1Ga(1-y1-y2)N (0<y1<1, 0≤y2<1) and having a dislocation along an intersection line of the principal plane of the nitride semiconductor substrate and a (0001) plane;
• and
• a device layer including an active layer provided on the underlayer,
• wherein an indium (In) content x1 of the first layer and an indium (In) content y1 of the second layer satisfy Expression (1) below:
• 0.5%≤y1<6%≤x1≤100% (1).