Indium gallium nitride light emitting diodes with reduced strain

A method of forming an LED emitter, the method comprising:

• providing a III-nitride layer on a substrate, the III-nitride layer having a planar top surface;
• providing discrete lateral growth regions on the planar top surface;
• selectively epitaxially growing, on each discrete lateral growth region, a base region comprising an In(x)Ga(1-x)N material, each base region extending in a direction perpendicular to the planar top surface;
• providing surfaces of the In(x)Ga(1-x)N material on portions of the base regions, the surfaces of the In(x)Ga(1-x)N material having a relaxed strain, the surfaces of the In(x)Ga(1-x)N material being characterized by a base lattice constant within 0.1% of its bulk relaxed value;
• and
• epitaxially growing LED regions on the surfaces, the LED regions comprising light-emitting layers of In(y1)Ga(1-y1)N material that are pseudomorphic with the surfaces of the In(x)Ga(1-x)N material, and characterized by an active region lattice constant within 0.1% of the base lattice constant,
• wherein 0.05<x<0.2 and y>0.3, and
• wherein the base regions and LED regions form mesas, and a surface of each mesa opposite the planar top surface has a lateral dimension that is smaller than a lateral dimension of the lateral growth region.