Patent ID: 7071490

Claim:
A semiconductor structure for light emitting devices that can emit in the red to ultraviolet portion of the electromagnetic spectrum, said structure comprising: an n-type single crystal silicon carbide substrate of a polytype selected from the group consisting of 3 C, 4 H, 6 H, and 15 R; a p-type layer formed of at least one Group III nitride selected from the group consisting of gallium nitride, indium nitride, and In x Ga 1-x N, where 0<x<1; an active layer of Al x In y Ga 1-x-y N, where 0≦x<1 and 0≦y≦1 and (x+y)≦1, wherein said active layer is n-type and is positioned between said silicon carbide substrate and said p-type layer; a first n-type cladding layer of Al x In y Ga 1-x-y N, where 0≦x≦1 and 0≦y≦1 and (x+y)≦1, wherein said first n-type cladding layer is positioned between said silicon carbide substrate and said active layer; a second n-type cladding layer of Al x In y Ga 1-x-y N, where 0≦x≦1 and 0≦y<1 and (x+y)≦1, wherein said second n-type cladding layer is positioned between said active layer and said p-type layer; wherein said first and second n-type cladding layers have respective bandgaps that are each larger than the bandgap of said active layer.