Semiconductor light emitting device

A semiconductor light emitting device comprising:

• a first conductivity type semiconductor layer including a superlattice structure, first semiconductor layers and second semiconductor layers being alternately provided in the superlattice structure, the first semiconductor layers including a first nitride semiconductor and the second semiconductor layers including a second nitride semiconductor having a larger lattice constant than the first nitride semiconductor;
• a light emitting layer provided on the first conductivity type semiconductor layer and including a multi-quantum well structure, quantum well layers and barrier layers being alternately provided in the multi-quantum well structure, the quantum well layers including a third nitride semiconductor having a smaller lattice constant than the second nitride semiconductor and the barrier layers including a fourth nitride semiconductor having a smaller lattice constant than the third nitride semiconductor, the quantum well layer on a side of the first conductivity type semiconductor layer having lattice spacing wider than the lattice constant of the third nitride semiconductor, the quantum well layer located at an end of the multi-quantum well structure opposite to the first conductivity type semiconductor layer having lattice spacing narrower than the lattice constant of the third nitride semiconductor;
• and
• a second conductivity type semiconductor layer provided on the light emitting layer.