Light emitting device grown on a relaxed layer

A method comprising:

• growing a first III-nitride semiconductor layer over a growth substrate;
• growing a second semiconductor layer;
• growing a third semiconductor layer;
• and
• growing a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region;
• wherein
• the second semiconductor layer is disposed between the first semiconductor layer and the third semiconductor layer;
• the third semiconductor layer is disposed between the second semiconductor layer and the light emitting layer, and the third semiconductor layer is a continuous layer of uniform composition that is as wide as the second semiconductor layer;
• a difference between an in-plane lattice constant of the first semiconductor layer and a bulk lattice constant of the third semiconductor layer is no more than 1%;
• a difference between an in-plane lattice constant of the first semiconductor layer and a bulk lattice constant of the second semiconductor layer is at least 1%;
• and
• the second semiconductor layer and the third semiconductor layer are at least partially relaxed.